JP4521947B2 - Pretreatment solution for electroless plating, treatment solution for electroless plating, and method for producing multilayer printed wiring board - Google Patents

Description

【００９２】
（式中、ｎは、２以上の整数を表す。）
【００９３】
【化２】

【００９４】
（式中、ｍは、２以上の整数を表す。また、Ｒ¹ 、Ｒ² は、メチレン基、エチレン基または−ＣＨ₂ −Ｏ−ＣＨ₂ −を表し、両者は同一であってもよいし、異なっていてもよい。）
【００９５】
また、上記化学式（２）で表される繰り返し単位を有する熱可塑性ポリフェニレンエーテル樹脂は、ベンゼン環にメチル基が結合した構造を有しているが、本発明で用いることのできるポリフェニレンエーテル樹脂としては、上記メチル基が、エチル基等の他のアルキル基等で置換された誘導体や、メチル基の水素がフッ素で置換された誘導体等であってもよい。
【００９６】
また、上記熱可塑性樹脂としては、フェノキシ樹脂、ポリエーテルスルフォン、ポリスルフォン等が挙げられる。
また、これらの複合体（樹脂複合体）としては、熱硬化性樹脂と熱可塑性樹脂とを含むものであれば特に限定されず、その具体例としては、例えば、粗化面形成用樹脂組成物等が挙げられる。
【００９７】
上記粗化面形成用樹脂組成物としては、例えば、酸、アルカリおよび酸化剤から選ばれる少なくとも１種からなる粗化液に対して難溶性の未硬化の耐熱性樹脂マトリックス中に、酸、アルカリおよび酸化剤から選ばれる少なくとも１種からなる粗化液に対して可溶性の物質が分散されたもの等が挙げられる。
なお、上記「難溶性」および「可溶性」という語は、同一の粗化液に同一時間浸漬した場合に、相対的に溶解速度の早いものを便宜上「可溶性」といい、相対的に溶解速度の遅いものを便宜上「難溶性」と呼ぶ。
【００９８】
上記耐熱性樹脂マトリックスとしては、層間樹脂絶縁層に上記粗化液を用いて粗化面を形成する際に、粗化面の形状を保持できるものが好ましく、例えば、熱硬化性樹脂、熱可塑性樹脂、これらの複合体等が挙げられる。また、感光性樹脂を用いることにより、層間樹脂絶縁層に露光、現像処理を用いてバイアホール用開口を形成してもよい。
【００９９】
上記熱硬化性樹脂としては、例えば、エポキシ樹脂、フェノール樹脂、ポリイミド樹脂、ポリオレフィン樹脂、フッ素樹脂等が挙げられる。また、上記熱硬化性樹脂を感光化する場合は、メタクリル酸やアクリル酸等を用い、熱硬化基を（メタ）アクリル化反応させる。特にエポキシ樹脂の（メタ）アクリレートが望ましい。さらに、１分子中に、２個以上のエポキシ基を有するエポキシ樹脂がより望ましい。上述の粗化面を形成することができるばかりでなく、耐熱性等にも優れているため、ヒートサイクル条件下においても、導体回路に応力の集中が発生せず、導体回路と層間樹脂絶縁層との間で剥離が発生しにくい。
【０１００】
上記熱可塑性樹脂としては、例えば、ポリエーテルスルフォン、ポリスルフォン、ポリフェニレンスルフォン、ポリフェニレンサルファイド、ポリフェニルエーテル、ポリエーテルイミド等が挙げられる。これらは単独で用いてもよいし、２種以上併用してもよい。
【０１０１】
上記酸、アルカリおよび酸化剤から選ばれる少なくとも１種からなる粗化液に対して可溶性の物質は、無機粒子、樹脂粒子、金属粒子、ゴム粒子、液相樹脂および液相ゴムから選ばれる少なくとも１種であることが望ましい。
【０１０２】
上記無機粒子としては、例えば、アルミニウム化合物、カルシウム化合物、カリウム化合物、マグネシウム化合物、ケイ素化合物等が挙げられる。これらは単独で用いてもよいし、２種以上併用してもよい。
【０１０３】
上記アルミニウム化合物としては、例えば、アルミナ、水酸化アルミニウム等が挙げられ、上記カルシウム化合物としては、例えば、炭酸カルシウム、水酸化カルシウム等が挙げられ、上記カリウム化合物としては、例えば、炭酸カリウム等が挙げられ、上記マグネシウム化合物としては、例えば、マグネシア、ドロマイト、塩基性炭酸マグネシウム、タルク等が挙げられ、上記ケイ素化合物としては、例えば、シリカ、ゼオライト等が挙げられる。これらは単独で用いてもよいし、２種以上併用してもよい。
【０１０４】
上記アルミナ粒子は、ふっ酸で溶解除去することができ、炭酸カルシウムは塩酸で溶解除去することができる。また、ナトリウム含有シリカやドロマイトはアルカリ水溶液で溶解除去することができる。
【０１０５】
上記樹脂粒子としては、例えば、熱硬化性樹脂、熱可塑性樹脂等からなるものが挙げられ、酸、アルカリおよび酸化剤から選ばれる少なくとも１種からなる粗化液に浸漬した場合に、上記耐熱性樹脂マトリックスよりも溶解速度の早いものであれば特に限定されず、具体的には、例えば、アミノ樹脂（メラミン樹脂、尿素樹脂、グアナミン樹脂等）、エポキシ樹脂、フェノール樹脂、フェノキシ樹脂、ポリイミド樹脂、ポリフェニレン樹脂、ポリオレフィン樹脂、フッ素樹脂、ビスマレイミド−トリアジン樹脂等挙げられる。これらは、単独で用いてもよく、２種以上併用してもよい。
【０１０６】
なお、上記エポキシ樹脂は、酸や酸化剤に溶解するものや、これらに難溶性のものを、オリゴマーの種類や硬化剤を選択することにより任意に製造することができる。例えば、ビスフェノールＡ型エポキシ樹脂をアミン系硬化剤で硬化させた樹脂はクロム酸に非常によく溶けるが、クレゾールノボラック型エポキシ樹脂をイミダゾール硬化剤で硬化させた樹脂は、クロム酸には溶解しにくい。
【０１０７】
上記樹脂粒子は予め硬化処理されていることが必要である。硬化させておかないと上記樹脂粒子が樹脂マトリックスを溶解させる溶剤に溶解してしまうため、均一に混合されてしまい、酸や酸化剤で樹脂粒子のみを選択的に溶解除去することができないからである。
【０１０８】
上記金属粒子としては、例えば、金、銀、銅、スズ、亜鉛、ステンレス、アルミニウム、ニッケル、鉄、鉛等が挙げられる。これらは、単独で用いてもよく、２種以上併用してもよい。
また、上記金属粒子は、絶縁性を確保するために、表層が樹脂等により被覆されていてもよい。
【０１０９】
上記ゴム粒子としては、例えば、アクリロニトリル−ブタジエンゴム、ポリクロロプレンゴム、ポリイソプレンゴム、アクリルゴム、多硫系剛性ゴム、フッ素ゴム、ウレタンゴム、シリコーンゴム、ＡＢＳ樹脂等が挙げられる。
【０１１０】
また、上記ゴム粒子として、例えば、ポリブタジエンゴム、エポキシ変性、ウレタン変性、（メタ）アクリロニトリル変性等の各種変性ポリブタジエンゴム、カルボキシル基を含有した（メタ）アクリロニトリル・ブタジエンゴム等を使用することもできる。これらのゴム粒子を使用することにより、該ゴム粒子が酸あるいは酸化剤に溶解しやすくなる。つまり、酸を用いてゴム粒子を溶解する際には、強酸以外の酸でも溶解することができ、酸化剤を用いてゴム粒子を溶解する際には、比較的酸化力の弱い過マンガン酸でも溶解することができる。また、クロム酸を用いた場合でも、低濃度で溶解することができる。そのため、酸や酸化剤が層間樹脂絶縁層表面に残留することがなく、後述するように、粗化面形成後、塩化パラジウム等の触媒を付与する際に、触媒が付与されなたかったり、触媒が酸化されたりすることがない。これらは、単独で用いてもよく、２種以上併用してもよい。
【０１１１】
上記可溶性の物質を、２種以上混合して用いる場合、混合する２種の可溶性の物質の組み合わせとしては、樹脂粒子と無機粒子との組み合わせが望ましい。両者とも導電性が低くいため、層間樹脂絶縁層の絶縁性を確保することができるとともに、難溶性樹脂との間で熱膨張の調整が図りやすく、粗化面形成用樹脂組成物からなる層間樹脂絶縁層にクラックが発生せず、層間樹脂絶縁層と導体回路との間で剥離が発生しないからである。
【０１１２】
上記液相樹脂としては、上記熱硬化性樹脂の未硬化溶液を使用することができ、このような液相樹脂の具体例としては、例えば、未硬化のエポキシオリゴマーとアミン系硬化剤の混合液等が挙げられる。
上記液相ゴムとしては、例えば、上記したポリブタジエンゴム、エポキシ変性、ウレタン変性、（メタ）アクリロニトリル変性等の各種変性ポリブタジエンゴム、カルボキシル基を含有した（メタ）アクリロニトリル・ブタジエンゴム等の未硬化溶液等を使用することができる。
【０１１３】
上記液相樹脂や液相ゴムを用いて上記感光性樹脂組成物を調製する場合には、耐熱性樹脂マトリックスと可溶性の物質とが均一に相溶しない（つまり相分離するように）ように、これらの物質を選択する必要がある。
上記基準により選択された耐熱性樹脂マトリックスと可溶性の物質とを混合することにより、上記耐熱性樹脂マトリックスの「海」の中に液相樹脂または液相ゴムの「島」が分散している状態、または、液相樹脂または液相ゴムの「海」の中に、耐熱性樹脂マトリックスの「島」が分散している状態の感光性樹脂組成物を調製することができる。
【０１１４】
そして、このような状態の感光性樹脂組成物を硬化させた後、「海」または「島」の液相樹脂または液相ゴムを除去することにより粗化面を形成することができる。
【０１１５】
上記粗化液として用いる酸としては、例えば、リン酸、塩酸、硫酸、硝酸や、蟻酸、酢酸等の有機酸等が挙げられるが、これらのなかでは有機酸を用いることが望ましい。粗化処理した場合に、バイアホールから露出する金属導体層を腐食させにくいからである。
上記酸化剤としては、例えば、クロム酸、クロム硫酸、アルカリ性過マンガン酸塩（過マンガン酸カリウム等）の水溶液等を用いることが望ましい。
また、上記アルカリとしては、水酸化ナトリウム、水酸化カリウム等の水溶液が望ましい。
【０１１６】
上記可溶性の物質の平均粒径は、１０μｍ以下が望ましい。
また、平均粒径が２μｍ以下の平均粒径の相対的に大きな粗粒子と平均粒径が相対的に小さな微粒子とを組み合わせて使用してもよい。即ち、平均粒径が０．１〜０．５μｍの可溶性の物質と平均粒径が１〜２μｍの可溶性の物質とを組み合わせる等である。
【０１１７】
このように、平均粒子と相対的に大きな粗粒子と平均粒径が相対的に小さな微粒子とを組み合わせることにより、無電解めっき膜の溶解残渣をなくし、めっきレジスト下のパラジウム触媒量を少なくし、さらに、浅くて複雑な粗化面を形成することができる。
さらに、複雑な粗化面を形成することにより、粗化面の凹凸が小さくても実用的なピール強度を維持することができる。
上記粗粒子は平均粒径が０．８μｍを超え２．０μｍ未満であり、微粒子は平均粒径が０．１〜０．８μｍであることが望ましい。
【０１１８】
上記粗粒子と微粒子とを組み合わせることにより、浅くて複雑な粗化面を形成することができるのは、使用する粒子径が粗粒子で平均粒径２μｍ未満であると、これらの粒子が溶解除去されても形成されるアンカーは浅くなり、また、除去される粒子は、相対的に粒子径の大きな粗粒子と相対的に粒子径の小さな微粒子の混合粒子であるから、形成される粗化面が複雑になるのである。このような複雑な粗化面を形成することにより、浅い粗化面でも実用的なピール強度を維持することができる。
【０１１９】
また、この場合、使用する粒子径が、粗粒子で平均粒径２μｍ未満であると、粗化が進行しすぎて空隙を発生させることはなく、形成した層間樹脂絶縁層は層間絶縁性に優れている。
なお、上記層間面形成用樹脂組成物において、可溶性の物質の粒径とは、可溶性の物質の一番長い部分の長さである。
【０１２０】
また、粗粒子は平均粒径が０．８μｍを超え２．０μｍ未満であり、微粒子は平均粒径が０．１〜０．８μｍであると、粗化面の深さは概ねＲｍａｘ＝３μｍ程度となり、セミアディテイブ法では、無電解めっき膜をエッチング除去しやすいだけではなく、無電解めっき膜下のＰｄ触媒をも簡単に除去することができ、また、実用的なピール強度１．０〜１．３ｋｇ／ｃｍを維持することができる。
【０１２１】
上記可溶性の物質の形状は特に限定されず、球状、破砕状等が挙げられる。また、上記可溶性の物質の形状は、一様な形状であることが望ましい。均一な粗さの凹凸を有する粗化面を形成することができるからである。
【０１２２】
上記粗化面形成用樹脂組成物は基板上等に塗布することができるように有機溶剤を含有するものであってもよいし、基板上等に圧着することができるようにフィルム状に成形されたもの（以下、粗化面形成用樹脂フィルムともいう）でもよい。
上記粗化面形成用樹脂組成物が有機溶剤を含有する場合、その含有量は、１０重量％以下であることが望ましい。
【０１２３】
上記粗化面形成用樹脂フィルムにおいて、上記可溶性の物質は、上記耐熱性樹脂マトリックス中にほぼ均一に分散されていることが望ましい。均一な粗さの凹凸を有する粗化面を形成することができ、樹脂フィルムにバイアホールやスルーホールを形成しても、その上に形成する導体回路の金属層の密着性を確保することができるからである。また、上記粗化面形成用樹脂フィルムは、粗化面を形成する表層部だけに可溶性の物質を含有するよう形成されていてもよい。それによって、粗化面形成用樹脂フィルムの表層部以外は酸または酸化剤にさらされることがないため、層間樹脂絶縁層を介した導体回路間の絶縁性が確実に保たれる。
【０１２４】
上記粗化面形成用樹脂フィルムにおいて、難溶性樹脂中に分散している可溶性の物質の配合量は、粗化面形成用樹脂フィルムに対して、３〜４０重量％が望ましい。可溶性の物質の配合量が３重量％未満では、所望の凹凸を有する粗化面を形成することができない場合があり、４０重量％を超えると、酸または酸化剤を用いて可溶性の物質を溶解した際に、樹脂フィルムの深部まで溶解してしまい、樹脂フィルムからなる層間樹脂絶縁層を介した導体回路間の絶縁性を維持できず、短絡の原因となる場合がある。
【０１２５】
上記粗化面形成用樹脂フィルムは、上記可溶性の物質、上記耐熱性樹脂マトリックス以外に、硬化剤、その他の成分等を含有していることが望ましい。
上記硬化剤としては、例えば、イミダゾール系硬化剤、アミン系硬化剤、グアニジン系硬化剤、これらの硬化剤のエポキシアダクトやこれらの硬化剤をマイクロカプセル化したもの、トリフェニルホスフィン、テトラフェニルホスフォニウム・テトラフェニルボレート等の有機ホスフィン系化合物等が挙げられる。
【０１２６】
上記硬化剤の含有量は、粗化面形成用樹脂フィルムに対して０．０５〜１０重量％であることが望ましい。０．０５重量％未満では、粗化面形成用樹脂フィルムの硬化が不充分であるため、酸や酸化剤が粗化面形成用樹脂フィルムに侵入する度合いが大きくなり、粗化面形成用樹脂フィルムの絶縁性が損なわれることがある。一方、１０重量％を超えると、過剰な硬化剤成分が樹脂の組成を変性させることがあり、信頼性の低下を招いたりしてしまうことがある。
【０１２７】
上記その他の成分としては、例えば、粗化面の形成に影響しない無機化合物あるいは樹脂等のフィラーが挙げられる。上記無機化合物としては、例えば、シリカ、アルミナ、ドロマイト等が挙げられ、上記樹脂としては、例えば、ポリイミド樹脂、ポリアクリル樹脂、ポリアミドイミド樹脂、ポリフェニレン樹脂、メラニン樹脂、オレフィン系樹脂等が挙げられる。これらのフィラーを含有させることによって、熱膨脹係数の整合や耐熱性、耐薬品性の向上等を図りプリント配線板の性能を向上させることができる。
【０１２８】
また、上記粗化面形成用樹脂フィルムは、溶剤を含有していてもよい。上記溶剤としては、例えば、アセトン、メチルエチルケトン、シクロヘキサノン等のケトン類、酢酸エチル、酢酸ブチル、セロソルブアセテートやトルエン、キシレン等の芳香族炭化水素等が挙げられる。これらは単独で用いてもよいし、２種以上併用してもよい。
【０１２９】
（７）次に、その材料として熱硬化性樹脂や樹脂複合体を用いた層間樹脂絶縁層を形成する場合には、未硬化の樹脂絶縁層に硬化処理を施すとともに、バイアホール用開口を形成し、層間樹脂絶縁層とする。また、この工程では、必要に応じて、貫通孔を形成してもよい。
上記バイアホール用開口は、レーザ処理により形成することが望ましい。上記レーザ処理は、上記硬化処理前に行ってもよいし、硬化処理後に行ってもよい。
また、感光性樹脂からなる層間樹脂絶縁層を形成した場合には、露光、現像処理を行うことにより、バイアホール用開口を設けてもよい。なお、この場合、露光、現像処理は、上記硬化処理前に行う。
【０１３０】
また、その材料として熱可塑性樹脂を用いた層間樹脂絶縁層を形成する場合には、熱可塑性樹脂からなる樹脂層にレーザ処理によりバイアホール用開口を形成し、層間樹脂絶縁層とすることができる。
【０１３１】
このとき、使用するレーザとしては、例えば、炭酸ガスレーザ、エキシマレーザ、ＵＶレーザ、ＹＡＧレーザ等が挙げられる。
これらのレーザは、形成するバイアホール用開口や貫通孔の形状等を考慮して使い分けてもよい。
【０１３２】
上記バイアホール用開口を形成する場合、マスクを介して、ホログラム方式のエキシマレーザによるレーザ光照射することにより、一度に多数のバイアホール用開口を形成することができる。
また、短パルスの炭酸ガスレーザを用いて、バイアホール用開口を形成すると、開口内の樹脂残りが少なく、開口周縁の樹脂に対するダメージが小さい。
【０１３３】
また、光学系レンズとマスクとを介してレーザ光を照射することにより、一度に多数のバイアホール用開口を形成することができる。
光学系レンズとマスクとを介することにより、同一強度で、かつ、照射角度が同一のレーザ光を複数の部分に同時に照射することができるからである。
【０１３４】
上記マスクに形成された貫通孔は、レーザ光のスポット形状を真円にするために、真円であることが望ましく、上記貫通孔の径は、０．１〜２ｍｍ程度が望ましい。
また、上記炭酸ガスレーザを用いる場合、そのパルス間隔は、１０^-4〜１０^-8秒であることが望ましい。また、開口を形成するためのレーザを照射する時間は、１０〜５００μ秒であることが望ましい。
【０１３５】
レーザ光にてバイアホール用開口を形成した場合、特に炭酸ガスレーザを用いた場合には、デスミア処理を行うことが望ましい。上記デスミア処理は、クロム酸、過マンガン酸塩等の水溶液からなる酸化剤を使用して行うことができる。また、酸素プラズマ、ＣＦ₄ と酸素の混合プラズマやコロナ放電等で処理してもよい。また、低圧水銀ランプを用いて紫外線を照射することにより、表面改質することもできる。
【０１３６】
上記層間樹脂絶縁層の厚さは特に限定されないが、５〜５０μｍが望ましい。
上記厚さが５μｍ未満であると、上下に隣合う導体回路間の絶縁性が維持できない場合があり、一方、５０μｍを超えると、バイアホール用開口等を形成した際に、その底部に樹脂残りが発生したり、そのバイアホール用開口等の形状が底部に向かって先細り形状になることがある。
また、上記バイアホール用開口の開口径は特に限定されないが、通常、４０〜２００μｍが望ましい。
【０１３７】
また、層間樹脂絶縁層を形成した基板に、貫通孔を形成する場合には、直径５０〜３００μｍのドリル、レーザ光等を用いて貫通孔を形成する。
上記貫通孔を形成した場合、後述する工程において、貫通孔の内壁面に導体層を形成することにより、スルーホールとすることができ、該スルーホールを形成することにより、上記基板および上記層間樹脂絶縁層を介した導体回路間を電気的に接続することができる。
【０１３８】
（８）次に、バイアホール用開口の内壁を含む層間樹脂絶縁層の表面と上記工程で貫通孔を形成した場合には貫通孔の内壁とに、必要に応じて、酸または酸化剤を用いて粗化面を形成する。
上記酸としては、硫酸、硝酸、塩酸、リン酸、蟻酸等が挙げられ、上記酸化剤としては、クロム酸、クロム硫酸、過マンガン酸ナトリウム等の過マンガン酸塩等が挙げられる。
また、上記粗化面の形成は、プラズマ処理等を用いて行ってもよい。
【０１３９】
具体的には、層間樹脂絶縁層を粗化面形成用樹脂組成物等を用いて形成した場合には、酸や酸化剤を用いて粗化面を形成することが望ましく、ポリオレフィン系樹脂等を用いて形成した場合には、プラズマ処理等を用いて粗化面を形成することが望ましい。
【０１４０】
この粗化面は、層間樹脂絶縁層とその上に形成する無電解めっき膜との密着性を高めるために形成するものであり、上記層間樹脂絶縁層と上記無電解めっき膜との間に充分な密着性がある場合には形成しなくてもよい。
【０１４１】
その後、酸を用いて粗化面を形成した場合はアルカリ等の水溶液を用い、酸化剤を用いて粗化面を形成した場合は中和液を用いて、バイアホール用開口内や貫通孔内を中和する。この操作により酸や酸化剤を除去し、次工程に影響を与えないようにする。
【０１４２】
（９）次に、形成された粗化面に、必要により、触媒を付与する。該触媒としては、上述したように、パラジウム等が挙げられる。
このとき、触媒を確実に付与するために、酸素、窒素等のプラズマ処理やコロナ処理等のドライ処理を施すことにより、酸または酸化剤の残渣を除去するとともに層間樹脂絶縁層の表面を改質することにより、触媒を確実に付与し、無電解めっき時の金属の析出、および、無電解めっき層の層間樹脂絶縁層への密着性を向上させることができ、特に、バイアホール用開口の底面において、大きな効果が得られる。
【０１４３】
（９）次に、バイアホール用開口の内壁面を含む層間樹脂絶縁層の表面に、上記した（Ａ）〜（Ｃ）の工程を含む方法を用いて無電解めっき膜を形成する。
ここで形成する無電解めっき膜の厚さは特に限定されないが、通常、６〜１２μｍ程度が望ましい。
【０１４４】
また、上記（７）の工程で貫通孔を形成した場合には、層間樹脂絶縁層上に導体回路を形成する際に、貫通孔の壁面にも上記した方法を用いて無電解めっき膜を形成することによりスルーホールとしてもよい。
【０１４５】
上記スルーホールを形成した場合には、以下のような処理工程を行うことが望ましい。即ち、無電解めっき層表面とスルーホール内壁とを黒化（酸化）−還元処理、有機酸と第二銅錯体との混合水溶液によるスプレー処理、Ｃｕ−Ｎｉ−Ｐ針状合金めっきによる処理等を用いて粗化形成処理を行う。この後、さらに、上記樹脂充填材等を充填し、ついで、樹脂充填材の表層部と無電解めっき膜表面とをバフ研磨等の研磨処理方法を用いて、平坦化する。
さらに、無電解めっきを行い、既に形成した無電解めっき膜と樹脂充填材の表層部とに無電解めっき層を形成することにより、スルーホールの上に蓋めっき層を形成する。
【０１４６】
（１１）次に、その表面に上記無電解めっき膜が形成された層間樹脂絶縁層形成配線板の上に上述した方法を用いてめっきレジストを形成する。ついで、めっきレジスト非形成部に、上述したように無電解めっき膜をめっきリードとして、電解めっき膜を形成する。
（１２）さらに、めっきレジストを強アルカリ水溶液で剥離した後にエッチングを行い、無電解めっき層を除去することにより、独立パターンの導体回路とする。
ここで用いるエッチング液としては、硫酸／過酸化水素水、塩化第二鉄、塩化第二銅、過硫酸アンモニウム等の過硫酸塩の水溶液、塩酸、硝酸、熱希硫酸等を用いることができる。また、第二銅錯体と有機酸とを含有するエッチング液を用いて、無電解めっき膜を除去するとともに、導体回路の表面に層間面を形成してもよい。
【０１４７】
（１３）次に、必要により、（５）に記載した方法と同様の方法で導体回路の粗化処理を行った後、（６）〜（１２）の工程を繰り返すことにより、導体回路と層間樹脂絶縁とが順次積層された基板を製造することができる。
【０１４８】
（１４）次に、最上層の導体回路を含む基板面にソルダーレジスト層を形成し、さらに、該ソルダーレジスト層を開口して半田パッドを形成した後、上記半田パッドに半田ペーストを充填し、リフローすることにより半田バンプを形成する。その後、外部基板接続面に、ピンを配設したり、半田ボールを形成したりすることにより、ＰＧＡ(Pin Grid Array)やＢＧＡ(Ball Grid Array) とする。
【０１４９】
上記ソルダーレジスト層は、例えば、ポリフェニレンエーテル樹脂、ポリオレフィン樹脂、フッ素樹脂、熱可塑性エラストマー、エポキシ樹脂、ポリイミド樹脂等からなるソルダーレジスト組成物を用いて形成することができ、これらの樹脂の具体例としては、例えば、層間樹脂絶縁層に用いた樹脂と同様の樹脂等が挙げられる。
【０１５０】
また、上記以外のソルダーレジスト組成物としては、例えば、ノボラック型エポキシ樹脂の（メタ）アクリレート、イミダゾール硬化剤、２官能性（メタ）アクリル酸エステルモノマー、分子量５００〜５０００程度の（メタ）アクリル酸エステルの重合体、ビスフェノール型エポキシ樹脂等からなる熱硬化性樹脂、多価アクリル系モノマー等の感光性モノマー、グリコールエーテル系溶剤などを含むペースト状の流動体が挙げられ、その粘度は２５℃で１〜１０Ｐａ・ｓに調整されていることが望ましい。
上記ノボラック型エポキシ樹脂の（メタ）アクリレートとしては、例えば、フェノールノボラックやクレゾールノボラックのグリシジルエーテルをアクリル酸やメタクリル酸等と反応させたエポキシ樹脂等が挙げられる。
【０１５１】
上記２官能性（メタ）アクリル酸エステルモノマーとしては特に限定されず、例えば、各種ジオール類のアクリル酸やメタクリル酸のエステル等が挙げられ、その市販品としては、日本化薬社製のＲ−６０４、ＰＭ２、ＰＭ２１等が挙げられる。
【０１５２】
また、上記ソルダーレジスト組成物は、エラストマーや無期フィラーが配合されていてもよい。
エラストマーが配合されていることにより、形成されるソルダーレジスト層は、エラスキマーの有する柔軟性および反発弾性により、ソルダーレジスト層に応力が作用した場合でも、該応力を吸収したり、緩和したりすることができ、その結果、多層プリント配線板の製造工程や製造した多層プリント配線板にＩＣチップ等の電子部品を搭載した後のソルダーレジスト層にクラックや剥離が発生することを抑制でき、さらに、クラックが発生した場合でも該クラックが大きく成長することができない。
【０１５３】
上記ソルダーレジスト層を開口する方法としては、例えば、バイアホール用開口を形成する方法と同様に、レーザ光を照射する方法等が挙げられる。
【０１５４】
また、ソルダーレジスト組成物として、感光性のソルダーレジスト組成物を使用した場合には、ソルダーレジスト層を形成した後、該ソルダーレジスト層上にフォトレジストを載置し、露光現像処理を施すことにより、ソルダーレジスト層を開口することができる。
【０１５５】
上記ソルダーレジスト層を開口することにより露出した導体回路部分は、通常、ニッケル、パラジウム、金、銀、白金等の耐食性金属により被覆することが望ましい。具体的には、ニッケル−金、ニッケル−銀、ニッケル−パラジウム、ニッケル−パラジウム−金等の金属により被覆層を形成することか望ましい。
上記被覆層は、例えば、めっき、蒸着、電着等により形成することができるが、これらのなかでは、被覆層の均一性に優れるという点からめっきが望ましい。
【０１５６】
なお、製品認識文字などを形成するための文字印刷工程やソルダーレジスト層の改質のために、酸素や四塩化炭素などのプラズマ処理を適時行ってもよい。
以上の方法は、セミアディティブ法によるものであるが、フルアディティブ法を採用してもよい。
【０１５７】
次に、第二の本発明の多層プリント配線板の製造方法について説明する。
第二の本発明の多層プリント配線板の製造方法は、基板上に導体回路と層間樹脂絶縁層とが順次積層され、これらの導体回路がバイアホールを介して接続されてなる多層プリント配線板の製造方法であって、少なくとも下記（ａ）〜（ｆ）の工程を含むことを特徴とする。
（ａ）上記基板または上記層間樹脂絶縁層の表面に触媒を付与する工程、
（ｂ）上記触媒の付与された上記基板または上記層間樹脂絶縁層に、本発明の無電解めっき用前処理液を用いて、前処理を施す工程、
（ｃ）樹脂基板または上記層間樹脂絶縁層上に無電解めっき膜を形成する工程、
（ｄ）上記無電解めっき膜上に電解めっき膜を形成する工程、
（ｅ）上記電解めっき膜上の一部に、エッチングレジストを形成する工程、および、
（ｆ）上記エッチングレジスト非形成部下の電解めっき膜と無電解めっき膜とをエッチング処理により除去する工程。
【０１５８】
第二の本発明の多層プリント配線板の製造方法によれば、基板や層間樹脂絶縁層の表面に本発明の無電解めっき用前処理液を用いて、前処理を施した後、無電解めっき処理、電解めっき処理等を施すことにより導体回路を形成するため、基板や層間樹脂絶縁層と導体回路との密着性が優れたものとなり、信頼性、電気特性に優れた多層プリント配線板を製造することができる。
【０１５９】
第二の本発明の多層プリント配線板の製造方法は、第一の本発明の多層プリント配線板の製造方法と比べて、（ａ）〜（ｆ）の工程、即ち、基板または層間樹脂絶縁層上に導体回路を形成する工程のみが異なるため、この（ａ）〜（ｆ）の工程についてのみ説明することとし、多層プリント配線板を製造する全製造工程の説明については省略することとする。
【０１６０】
第二の本発明の多層プリント配線板の製造方法においては、基板または層間樹脂絶縁層の表面に触媒を付与する。
上記触媒としては、例えば、パラジウム金属等が挙げられる。
また、第二の本発明の多層プリント配線板の製造方法においても、基板または層間樹脂絶縁層の表面には、触媒を付与する前に、予め、粗化面を形成しておくことが望ましい。
上記触媒としてパラジウム金属を用いる場合、触媒を付与する方法としては、第一の本発明の多層プリント配線板の製造方法と同様の方法を用いることができる。
【０１６１】
次に、上記触媒の付与された上記基板または上記層間樹脂絶縁層に、本発明の無電解めっき用前処理液を用いて、前処理を施す。
上記前処理は、基板や層間樹脂絶縁層形成配線板を上記無電解めっき用前処理液中に浸漬することにより行う。
【０１６２】
このとき、上記無電解めっき用前処理液の温度は、第一の本発明の多層プリント配線板の製造方法と同様、２０〜５０℃が望ましい。
また、上記無電解めっき用前処理液中ヘの浸漬時間も、第一の本発明の多層プリント配線板の製造方法と同様、０．５〜５分間であることが望ましい。
【０１６３】
次に、上記前処理を施した基板または層間樹脂絶層上に無電解めっき膜を形成する。
上記無電解めっき膜は、基板や層間樹脂絶縁層形成配線板を無電解めっき液中に浸漬することにより形成することができる。ここで、無電解めっき液としては、第一の本発明の多層プリント配線板の製造方法と同様のものを用いることができる。
【０１６４】
次に、上記無電解めっき膜上に電解めっき膜を形成する。
上記電解めっき膜を形成は、既に形成した無電解めっき膜をめっきリードとして行うことができる。
具体的には、例えば、硫酸、硫酸銅および添加剤を含む電解めっき液を用いることにより電解銅めっき膜を形成することができる。
【０１６５】
次に、上記電解めっき膜の一部、即ち、導体回路形成部分に相当する部分にエッチングレジストを形成する。
上記エッチングレジストは、例えば、感光性ドライフィルムを張り付けたり、液状レジストを塗布した後、露光現像処理を施すことにより形成することができる。
【０１６６】
次に、エッチング処理を施すことにより、導体回路非形成部の電解めっき膜、無電解めっき膜を除去し、その後、エッチングレジストを強アルカリ水溶液で剥離する。
上記エッチング処理としては、硫酸／過酸化水素水溶液、塩化第二鉄、塩化第二銅、過硫酸アンモニウムなどの過硫酸塩の水溶液等をエッチング液として用いた化学エッチング、イオンビームエッチング等による物理エッチング等が使用される。
【０１６７】
このような工程を経ることにより、基板上や層間樹脂絶縁層上に導体回路を形成することができる。
また、第二の本発明の多層プリント配線板の製造方法では、無電解めっき膜を形成する前に、本発明の無電解めっき用前処理液を用いて、基板や層間樹脂絶縁層の表面に前処理を施しているため、基板や層間樹脂絶縁層との密着性に優れた導体回路を形成することができる。
【０１６８】
次に、第三の本発明の多層プリント配線板の製造方法について説明する。
第三の本発明の多層プリント配線板の製造方法は、基板上に導体回路と層間樹脂絶縁層とが順次積層され、これらの導体回路がバイアホールを介して接続されてなる多層プリント配線板の製造方法であって、少なくとも下記（Ａ）〜（Ｅ）の工程を含むことを特徴とする。
（Ａ）上記基板または上記層間樹脂絶縁層の表面に触媒を付与する工程、
（Ｂ）上記触媒の付与された上記基板または上記層間樹脂絶縁層に、本発明の無電解めっき用処理液を用いて、前処理を施した後、上記基板または上記層間樹脂絶縁層上に無電解めっき膜を形成する工程、
（Ｃ）上記無電解めっき膜の一部にめっきレジストを形成する工程、
（Ｄ）上記めっきレジスト非形成部に電解めっき膜を形成する工程、および、
（Ｅ）上記めっきレジストを剥離した後、上記めっきレジスト下の無電解めっき膜を除去する工程。
【０１６９】
第三の本発明の多層プリント配線板の製造方法によれば、本発明の無電解めっき用処理液を用いて、基板や層間樹脂絶縁層の表面に前処理を施した後、無電解めっき処理を施し、さらに、電解めっき処理等を施すことにより導体回路を形成するため、基板や層間樹脂絶縁層と導体回路との密着性が優れたものとなり、信頼性、電気特性に優れた多層プリント配線板を製造することができる。
【０１７０】
第三の本発明の多層プリント配線板の製造方法は、第一の本発明の多層プリント配線板の製造方法と比べて、本発明の無電解めっき用処理液を用いて、基板や層間樹脂絶縁層の表面に前処理を施した後、無電解めっき処理を施すことのみが異なる。
即ち、第一の本発明の多層プリント配線板の製造方法では、無電解めっき膜を形成する際に用いる無電解めっき液は特に限定されなかったのに対し、第三の本発明の多層プリント配線板の製造方法では、「アルカリ性化合物、還元剤、銅イオン、および、酒石酸もしくはその塩を含む水溶液からなる無電解めっき液」を用いて、無電解めっき膜を形成することを特徴とする。
【０１７１】
そこで、ここでは、上記無電解めっき膜を形成する方法についてのみ説明することとする。
上記無電解めっき膜の形成は、その表面に前処理の施された基板や層間樹脂絶縁層形成配線板を、本発明の無電解めっき用処理液を構成する無電解めっき液中に浸漬することにより行う。
上記基板や層間樹脂絶縁層形成配線板を無電解めっき液中に浸漬する際の条件としては特に限定されず、無電解めっき液の組成や被めっき物の材質等を考慮して適宜選択すればよい。具体的には、例えば、２５〜３５℃の無電解めっき液中に、１０〜２０分間浸漬することにより無電解めっき膜を形成することができる。
【０１７２】
次に、第四の本発明の多層プリント配線板の製造方法について説明する。
第四の本発明の多層プリント配線板の製造方法は、基板上に導体回路と層間樹脂絶縁層とが順次積層され、これらの導体回路がバイアホールを介して接続されてなる多層プリント配線板の製造方法であって、少なくとも下記（ａ）〜（ｅ）の工程を含むことを特徴とする。
（ａ）上記基板または上記層間樹脂絶縁層の表面に触媒を付与する工程、
（ｂ）上記触媒の付与された上記基板または上記層間樹脂絶縁層に、本発明の無電解めっき用処理液を用いて、前処理を施した後、上記基板または上記層間樹脂絶縁層上に無電解めっき膜を形成する工程、
（ｃ）上記無電解めっき膜上に電解めっき膜を形成する工程、
（ｄ）上記電解めっき膜上の一部に、エッチングレジストを形成する工程、および、
（ｅ）上記エッチングレジスト非形成部下の電解めっき膜と無電解めっき膜とをエッチング処理により除去する工程。
【０１７３】
第四の本発明の多層プリント配線板の製造方法によれば、本発明の無電解めっき用処理液を用いて、基板や層間樹脂絶縁層の表面に前処理を施した後、無電解めっき処理を施し、さらに、電解めっき処理等を施すことにより導体回路を形成するため、基板や層間樹脂絶縁層と導体回路との密着性が優れたものとなり、信頼性、電気特性に優れた多層プリント配線板を製造することができる。
【０１７４】
第四の本発明の多層プリント配線板の製造方法は、第二の本発明の多層プリント配線板の製造方法と比べて、本発明の無電解めっき用処理液を用いて、基板や層間樹脂絶縁層の表面に前処理を施した後、無電解めっき処理を施すことのみが異なる。
即ち、第二の本発明の多層プリント配線板の製造方法では、無電解めっき膜を形成する際に用いる無電解めっき液は特に限定されなかったのに対し、第四の本発明の多層プリント配線板の製造方法では、「アルカリ性化合物、還元剤、銅イオン、および、酒石酸もしくはその塩を含む水溶液からなる無電解めっき液」を用いて、無電解めっき膜を形成することを特徴とする。
【０１７５】
そこで、ここでは、上記無電解めっき膜を形成する方法についてのみ説明することとする。
上記無電解めっき膜の形成は、その表面に前処理の施された基板や層間樹脂絶縁層形成配線板を、本発明の無電解めっき用処理液を構成する無電解めっき液中に浸漬することにより行う。
上記基板や層間樹脂絶縁層形成配線板を無電解めっき液中に浸漬する際の条件としては特に限定されず、無電解めっき液の組成や被めっき物の材質等を考慮して適宜選択すればよい。具体的には、例えば、２５〜３５℃の無電解めっき液中に、１０〜２０分間浸漬することにより無電解めっき膜を形成することができる。
【０１７６】
【実施例】
以下、本発明をさらに詳細に説明する。
（実施例１）
Ａ．層間樹脂絶縁層用の樹脂フィルムの作製
ビスフェノールＡ型エポキシ樹脂（エポキシ当量４６９、油化シェルエポキシ社製エピコート１００１）３０重量部、クレゾールノボラック型エポキシ樹脂（エポキシ当量２１５、大日本インキ化学工業社製 エピクロンＮ−６７３）４０重量部、トリアジン構造含有フェノールノボラック樹脂（フェノール性水酸基当量１２０、大日本インキ化学工業社製 フェノライトＫＡ−７０５２）３０重量部をエチルジグリコールアセテート２０重量部、ソルベントナフサ２０重量部に攪拌しながら加熱溶解させ、そこへ末端エポキシ化ポリブタジエンゴム（ナガセ化成工業社製 デナレックスＲ−４５ＥＰＴ）１５重量部と２−フェニル−４、５−ビス（ヒドロキシメチル）イミダゾール粉砕品１．５重量部、微粉砕シリカ２重量部、シリコン系消泡剤０．５重量部を添加しエポキシ樹脂組成物を調製した。
得られたエポキシ樹脂組成物を厚さ３８μｍのＰＥＴフィルム上に乾燥後の厚さが５０μｍとなるようにロールコーターを用いて塗布した後、８０〜１２０℃で１０分間乾燥させることにより、層間樹脂絶縁層用樹脂フィルムを作製した。
【０１７７】
Ｂ．樹脂充填材の調製
ビスフェノールＦ型エポキシモノマー（油化シェル社製、分子量：３１０、ＹＬ９８３Ｕ）１００重量部、表面にシランカップリング剤がコーティングされた平均粒径が１．６μｍで、最大粒子の直径が１５μｍ以下のＳｉＯ₂ 球状粒子（アドテック社製、ＣＲＳ １１０１−ＣＥ）１７０重量部およびレベリング剤（サンノプコ社製 ペレノールＳ４）１．５重量部を容器にとり、攪拌混合することにより、その粘度が２３±１℃で４５〜４９Ｐａ・ｓの樹脂充填材を調製した。なお、硬化剤として、イミダゾール硬化剤（四国化成社製、２Ｅ４ＭＺ−ＣＮ）６．５重量部を用いた。
【０１７８】
Ｃ．多層プリント配線板の製造
（１）厚さ０．８ｍｍのガラスエポキシ樹脂またはＢＴ（ビスマレイミドトリアジン）樹脂からなる絶縁性基板１の両面に１８μｍの銅箔８がラミネートされている銅張積層板を出発材料とした（図１（ａ）参照）。まず、この銅張積層板をドリル削孔し、無電解めっき処理を施し、パターン状にエッチングすることにより、基板の両面に下層導体回路４とスルーホール９を形成した。
【０１７９】
（２）スルーホール９および下層導体回路４を形成した基板を水洗いし、乾燥した後、ＮａＯＨ（１０ｇ／ｌ）、ＮａＣｌＯ₂ （４０ｇ／ｌ）、Ｎａ₃ ＰＯ₄ （６ｇ／ｌ）を含む水溶液を黒化浴（酸化浴）とする黒化処理、および、ＮａＯＨ（１０ｇ／ｌ）、ＮａＢＨ₄ （６ｇ／ｌ）を含む水溶液を還元浴とする還元処理を行い、そのスルーホール９を含む下層導体回路４の全表面に粗化面４ａ、９ａを形成した（図１（ｂ）参照）。
【０１８０】
（３）上記Ｂに記載した樹脂充填材を調製した後、下記の方法により調製後２４時間以内に、スルーホール９内、および、基板１の片面の導体回路非形成部と導体回路４の外縁部とに樹脂充填材１０の層を形成した。
すなわち、まず、スキージを用いてスルーホール内に樹脂充填材を押し込んだ後、１００℃、２０分の条件で乾燥させた。次に、導体回路非形成部に相当する部分が開口したマスクを基板上に載置し、スキージを用いて凹部となっている導体回路非形成部に樹脂充填材１０の層を形成し、１００℃、２０分の条件で乾燥させた（図１（ｃ）参照）。
【０１８１】
（４）上記（３）の処理を終えた基板の片面を、＃６００のベルト研磨紙（三共理化学製）を用いたベルトサンダー研磨により、内層銅パターン４の表面やスルーホール９のランド表面に樹脂充填材１０が残らないように研磨し、次いで、上記ベルトサンダー研磨による傷を取り除くためのバフ研磨を行った。このような一連の研磨を基板の他方の面についても同様に行った。
次いで、１００℃で１時間、１５０℃で１時間の加熱処理を行って樹脂充填材１０を硬化した。
【０１８２】
このようにして、スルーホール９や導体回路非形成部に形成された樹脂充填材１０の表層部および下層導体回路４の表面を平坦化し、樹脂充填材１０と下層導体回路４の側面４ａとが粗化面を介して強固に密着し、またスルーホール９の内壁面９ａと樹脂充填材１０とが粗化面を介して強固に密着した基板を得た（図１（ｄ）参照）。即ち、この工程により、樹脂充填材１０の表面と下層導体回路４の表面とが同一平面となる。
【０１８３】
（５）上記基板を水洗、酸性脱脂した後、ソフトエッチングし、次いで、エッチング液を基板の両面にスプレイで吹きつけて、下層導体回路４の表面とスルーホール９のランド表面と内壁とをエッチングすることにより、下層導体回路４の全表面に粗化面４ａ、９ａを形成した（図２（ａ）参照）。
エッチング液としては、イミダゾール銅（ＩＩ）錯体１０重量部、グリコール酸７重量部、塩化カリウム５重量部からなるエッチング液（メック社製、メックエッチボンド）を使用した。
【０１８４】
（６）基板の両面に、Ａで作製した基板より少し大きめの層間樹脂絶縁層用樹脂フィルムを基板上に載置し、圧力４ｋｇｆ／ｃｍ² 、温度８０℃、圧着時間１０秒の条件で仮圧着して裁断した後、さらに、以下の方法により真空ラミネーター装置を用いて貼り付けることにより層間樹脂絶縁層を形成した（図３（ｂ）参照）。すなわち、層間樹脂絶縁層用樹脂フィルムを基板上に、真空度０．５Ｔｏｒｒ、圧力４ｋｇｆ／ｃｍ² 、温度８０℃、圧着時間６０秒の条件で本圧着し、その後、１７０℃で３０分間熱硬化させた。
【０１８５】
（７）次に、層間樹脂絶縁層２上に、厚さ１．２ｍｍの貫通孔が形成されたマスクを介して、波長１０．４μｍのＣＯ₂ ガスレーザにて、ビーム径４．０ｍｍ、トップハットモード、パルス幅８．０μ秒、マスクの貫通孔の径１．０ｍｍ、１ショットの条件で層間樹脂絶縁層２に、直径８０μｍのバイアホール用開口６を形成した（図２（ｃ）参照）。
【０１８６】
（８）バイアホール用開口６を形成した基板を、６０ｇ／ｌの過マンガン酸を含む８０℃の溶液に１０分間浸漬し、層間樹脂絶縁層２の表面に存在するエポキシ樹脂粒子を溶解除去することにより、バイアホール用開口６の内壁を含む層間樹脂絶縁層２の表面を粗面とした（図２（ｄ）参照）。
【０１８７】
（９）次に、上記処理を終えた基板を、中和溶液（シプレイ社製）に浸漬してから水洗いした。
さらに、粗面化処理（粗化深さ３μｍ）した該基板の表面に、パラジウム触媒を付与することにより、層間樹脂絶縁層２の表面およびバイアホール用開口６の内壁面に触媒核を付着させた（図示せず）。すなわち、上記基板を塩化パラジウム（ＰｂＣｌ₂ ）と塩化第一スズ（ＳｎＣｌ₂ ）とを含む触媒液中に浸漬し、パラジウム金属を析出させることにより触媒を付与した。
【０１８８】
（１０）次に、以下の組成の無電解めっき用前処理液中に基板を浸漬することにより前処理を施した。
〔無電解めっき用前処理液〕
ＮａＯＨ ０．１０ｍｏｌ／ｌ
ＨＣＨＯ ０．１０ｍｏｌ／ｌ
〔前処理条件〕
浸漬温度 ３０℃
液温度 ３分
【０１８９】
（１１）次に、以下の組成の無電解銅めっき水溶液中に、前処理を施した基板を浸漬して、粗面全体に厚さ０．６〜３．０μｍの無電解銅めっき膜１２を形成し、バイアホール用開口の内壁を含む層間樹脂絶縁層の表面に無電解銅めっき膜１２が形成された基板を得た（図３（ａ）参照）。
〔無電解めっき水溶液〕
ＮｉＳＯ₄ ０．００３ ｍｏｌ／ｌ
酒石酸 ０．２００ ｍｏｌ／ｌ
硫酸銅 ０．０３０ ｍｏｌ／ｌ
ＨＣＨＯ ０．０５０ ｍｏｌ／ｌ
ＮａＯＨ ０．１００ ｍｏｌ／ｌ
α、α′−ビピリジル １００ ｍｇ／ｌ
ポリエチレングリコール（ＰＥＧ） ０．１０ ｇ／ｌ
〔無電解めっき条件〕
３４℃の液温度で４０分
【０１９０】
（１２）無電解銅めっき膜１２が形成された基板に市販の感光性ドライフィルムを張り付け、マスクを載置して、１００ｍＪ／ｃｍ² で露光し、０．８％炭酸ナトリウム水溶液で現像処理することにより、厚さ２０μｍのめっきレジスト３を設けた（図３（ｂ）参照）。
【０１９１】
（１３）ついで、基板を５０℃の水で洗浄して脱脂し、２５℃の水で水洗後、さらに硫酸で洗浄してから、以下の条件で電解めっきを施し、めっきレジスト３非形成部に、厚さ２０μｍの電解銅めっき膜１３を形成した（図３（ｃ）参照）。
〔電解めっき液〕
硫酸 ２．２４ ｍｏｌ／ｌ
硫酸銅 ０．２６ ｍｏｌ／ｌ
添加剤 １９．５ ｍｌ／ｌ
（アトテックジャパン社製、カパラシドＧＬ）
〔電解めっき条件〕
電流密度 １ Ａ／ｄｍ²
時間 ６５ 分
温度 ２２±２ ℃
【０１９２】
（１４）さらに、めっきレジスト３を５％ＫＯＨで剥離除去した後、そのめっきレジスト３下の無電解めっき膜を硫酸と過酸化水素との混合液でエッチング処理して溶解除去し、独立の上層導体回路５（バイアホール７を含む）とした（図３（ｄ）参照）。
【０１９３】
（１５）ついで、上記（５）と同様の処理を行い、導体回路表面に粗化面を形成した（図４（ａ）参照）。
（１６）上記（６）〜（１５）の工程を繰り返すことにより、さらに上層の導体回路を形成し、多層配線板を得た（図４（ｂ）〜図５（ｂ）参照）。
【０１９４】
（１７）次に、ジエチレングリコールジメチルエーテル（ＤＭＤＧ）に６０重量％の濃度になるように溶解させた、クレゾールノボラック型エポキシ樹脂（日本化薬社製）のエポキシ基５０％をアクリル化した感光性付与のオリゴマー（分子量：４０００）４６．６７重量部、メチルエチルケトンに溶解させた８０重量％のビスフェノールＡ型エポキシ樹脂（油化シェル社製、商品名：エピコート１００１）１５．０重量部、イミダゾール硬化剤（四国化成社製、商品名：２Ｅ４ＭＺ−ＣＮ）１．６重量部、感光性モノマーである２官能アクリルモノマー（日本化薬社製、商品名：Ｒ６０４）４．５重量部、同じく多価アクリルモノマー（共栄化学社製、商品名：ＤＰＥ６Ａ）１．５重量部、分散系消泡剤（サンノプコ社製、Ｓ−６５）０．７１重量部を容器にとり、攪拌、混合して混合組成物を調製し、この混合組成物に対して光重合開始剤としてベンゾフェノン（関東化学社製）２．０重量部、光増感剤としてのミヒラーケトン（関東化学社製）０．２重量部、を加えることにより、粘度を２５℃で２．０Ｐａ・ｓに調整したソルダーレジスト組成物を得た。
なお、粘度測定は、Ｂ型粘度計（東京計器社製、ＤＶＬ−Ｂ型）で６０ｒｐｍの場合はローターＮｏ．４、６ｒｐｍの場合はローターＮｏ．３によった。
【０１９５】
（１８）次に、多層配線基板の両面に、上記ソルダーレジスト組成物を２０μｍの厚さで塗布し、７０℃で２０分間、７０℃で３０分間の条件で乾燥処理を行った後、ソルダーレジスト開口部のパターンが描画された厚さ５ｍｍのフォトマスクをソルダーレジスト層に密着させて１０００ｍＪ／ｃｍ² の紫外線で露光し、ＤＭＴＧ溶液で現像処理し、２００μｍの直径の開口を形成した。
そして、さらに、８０℃で１時間、１００℃で１時間、１２０℃で１時間、１５０℃で３時間の条件でそれぞれ加熱処理を行ってソルダーレジスト層を硬化させ、開口を有し、その厚さが２０μｍのソルダーレジストパターン層１４を形成した。上記ソルダーレジスト組成物としては、市販のソルダーレジスト組成物を使用することもできる。
【０１９６】
（１９）次に、ソルダーレジスト層１４を形成した基板を、塩化ニッケル（２．３×１０^-1ｍｏｌ／ｌ）、次亜リン酸ナトリウム（２．８×１０^-1ｍｏｌ／ｌ）、クエン酸ナトリウム（１．６×１０^-1ｍｏｌ／ｌ）を含むｐＨ＝４．５の無電解ニッケルめっき液に２０分間浸漬して、開口部に厚さ５μｍのニッケルめっき層１５を形成した。さらに、その基板をシアン化金カリウム（７．６×１０^-3ｍｏｌ／ｌ）、塩化アンモニウム（１．９×１０^-1ｍｏｌ／ｌ）、クエン酸ナトリウム（１．２×１０^-1ｍｏｌ／ｌ）、次亜リン酸ナトリウム（１．７×１０^-1ｍｏｌ／ｌ）を含む無電解金めっき液に８０℃の条件で７．５分間浸漬して、ニッケルめっき層１５上に、厚さ０．０３μｍの金めっき層１６を形成した。
【０１９７】
（２０）この後、基板のＩＣチップを載置する面のソルダーレジスト層１４の開口に、スズ−鉛を含有するはんだペーストを印刷し、さらに他方の面のソルダーレジスト層１４の開口にスズ−アンチモンを含有するはんだペーストを印刷した後、２００℃でリフローすることによりはんだバンプ（はんだ体）１７を形成し、はんだバンプ１７を有する多層プリント配線板を製造した（図５（ｃ）参照）。
【０１９８】
（実施例２）
無電解めっき用前処理液におけるＮａＯＨの濃度を、０．０２５ｍｏｌ／ｌにした以外は、実施例１と同様にして多層プリント配線板を製造した。
【０１９９】
（実施例３）
無電解めっき用前処理液におけるＨＣＨＯの濃度を、０．１０ｍｏｌ／ｌにした以外は、実施例１と同様にして多層プリント配線板を製造した。
【０２００】
（実施例４）
無電解めっき液において、ＮｉＳＯ₄ の代わりに、ＣｏＳＯ₄ （濃度：０．００２ｍｏｌ／ｌを用いた以外は、実施例１と同様にして多層プリント配線板を製造した。
【０２０１】
（実施例５）
Ａ．上層の粗化面形成用樹脂組成物の調製
（１）クレゾールノボラック型エポキシ樹脂（日本化薬社製、分子量：２５００）の２５％アクリル化物を８０重量％の濃度でジエチレングリコールジメチルエーテル（ＤＭＤＧ）に溶解させた樹脂液４００重量部、感光性モノマー（東亜合成社製、アロニックスＭ３２５）６０重量部、消泡剤（サンノプコ社製 Ｓ−６５）５重量部およびＮ−メチルピロリドン（ＮＭＰ）３５重量部を容器にとり、攪拌混合することにより混合組成物を調製した。
【０２０２】
（２）ポリエーテルスルフォン（ＰＥＳ）８０重量部、エポキシ樹脂粒子（三洋化成社製、ポリマーポール）の平均粒径１．０μｍのもの７２重量部および平均粒径０．５μｍのもの３１重量部を別の容器にとり、攪拌混合した後、さらにＮＭＰ２５７重量部を添加し、ビーズミルで攪拌混合し、別の混合組成物を調製した。
【０２０３】
（３）イミダゾール硬化剤（四国化成社製、２Ｅ４ＭＺ−ＣＮ）２０重量部、光重合開始剤（ベンゾフェノン）２０重量部、光増感剤（チバ・スペシャルティ・ケミカルズ社製、ＥＡＢ）４重量部およびＮＭＰ１６重量部をさらに別の容器にとり、攪拌混合することにより混合組成物を調製した。
そして、（１）、（２）および（３）で調製した混合組成物を混合することにより粗化面形成用樹脂組成物を得た。
【０２０４】
Ｂ．下層の粗化面形成用樹脂組成物の調製
（１）クレゾールノボラック型エポキシ樹脂（日本化薬社製、分子量：２５００）の２５％アクリル化物を８０重量％の濃度でジエチレングリコールジメチルエーテル（ＤＭＤＧ）に溶解させた樹脂液４００重量部、感光性モノマー（東亜合成社製、アロニックスＭ３２５）６０重量部、消泡剤（サンノプコ社製 Ｓ−６５）５重量部およびＮ−メチルピロリドン（ＮＭＰ）３５重量部を容器にとり、攪拌混合することにより混合組成物を調製した。
【０２０５】
（２）ポリエーテルスルフォン（ＰＥＳ）８０量部、および、エポキシ樹脂粒子（三洋化成社製、ポリマーポール）の平均粒径０．５μｍのもの１４５重量部を別の容器にとり、攪拌混合した後、さらにＮＭＰ２８５重量部を添加し、ビーズミルで攪拌混合し、別の混合組成物を調製した。
【０２０６】
（３）イミダゾール硬化剤（四国化成社製、２Ｅ４ＭＺ−ＣＮ）２０重量部、光重合開始剤（ベンゾフェノン）２０重量部、光増感剤（チバ・スペシャルティ・ケミカルズ社製、ＥＡＢ）４重量部およびＮＭＰ１６重量部をさらに別の容器にとり、攪拌混合することにより混合組成物を調製した。
そして、（１）、（２）および（３）で調製した混合組成物を混合することにより無電解めっき用接着剤を得た。
【０２０７】
Ｃ．樹脂充填剤の調製
実施例１と同様にして、樹脂充填材を調製した。
【０２０８】
Ｄ．プリント配線板の製造方法
（１）厚さ０．８ｍｍのガラスエポキシ樹脂またはＢＴ（ビスマレイミドトリアジン）樹脂からなる基板１の両面に１８μｍの銅箔８がラミネートされている銅張積層板を出発材料とした（図６（ａ）参照）。まず、この銅張積層板をドリル削孔し、無電解めっき処理を施し、パターン状にエッチングすることにより、基板１の両面に下層導体回路４とスルーホール９を形成した。
【０２０９】
（２）スルーホール９および下層導体回路４を形成した基板を水洗いし、乾燥した後、ＮａＯＨ（１０ｇ／ｌ）、ＮａＣｌＯ₂ （４０ｇ／ｌ）、Ｎａ₃ ＰＯ₄ （１６ｇ／ｌ）を含む水溶液を黒化浴（酸化浴）とする黒化処理、および、ＮａＯＨ（１９ｇ／ｌ）、ＮａＢＨ₄ （５ｇ／ｌ）を含む水溶液を還元浴とする還元処理を行い、そのスルーホール９を含む下層導体回路４の全表面に粗化面４ａ、９ａを形成した（図６（ｂ）参照）。
【０２１０】
（３）上記Ｃに記載した樹脂充填材を調製した後、下記の方法により調製後２４時間以内に、スルーホール９内、および、基板１の片面の導体回路非形成部と導体回路４の外縁部とに樹脂充填材１０の層を形成した。
すなわち、まず、スキージを用いてスルーホール内に樹脂充填材を押し込んだ後、１００℃、２０分の条件で乾燥させた。次に、導体回路非形成部に相当する部分が開口したマスクを基板上に載置し、スキージを用いて凹部となっている導体回路非形成部に樹脂充填材１０の層を形成し、１００℃、２０分の条件で乾燥させた（図６（ｃ）参照）。
【０２１１】
（４）上記（３）の処理を終えた基板の片面を、＃６００のベルト研磨紙（三共理化学製）を用いたベルトサンダー研磨により、内層銅パターン４の表面やスルーホール９のランド表面に樹脂充填材１０が残らないように研磨し、次いで、上記ベルトサンダー研磨による傷を取り除くためのバフ研磨を行った。このような一連の研磨を基板の他方の面についても同様に行った。
次いで、１００℃で１時間、１２０℃で３時間、１５０℃で１時間、１８０℃で７時間の加熱処理を行って樹脂充填材１０を硬化した。
【０２１２】
このようにして、スルーホール９や導体回路非形成部に形成された樹脂充填材１０の表層部および下層導体回路４の表面を平坦化し、樹脂充填材１０と下層導体回路４の側面４ａとが粗化面を介して強固に密着し、またスルーホール９の内壁面９ａと樹脂充填材１０とが粗化面を介して強固に密着した絶縁性基板を得た（図６（ｄ）参照）。この工程により、樹脂充填材１０の表面と下層導体回路４の表面が同一平面となる。
【０２１３】
（５）上記基板を水洗、酸性脱脂した後、ソフトエッチングし、次いで、エッチング液を基板の両面にスプレイで吹きつけて、下層導体回路４の表面とスルーホール９のランド表面と内壁とをエッチングすることにより、下層導体回路４の全表面に粗化面４ａ、９ａを形成した（図７（ａ）参照）。エッチング液として、イミダゾール銅（II）錯体１０重量部、グリコール酸７重量部、塩化カリウム５重量部からなるエッチング液（メック社製、メックエッチボンド）を使用した。
【０２１４】
（６）基板の両面に、上記Ｂの粗化面形成用樹脂組成物（粘度：１．５Ｐａ・ｓ）をロールコータで塗布し、水平状態で２０分間放置してから、６０℃で３０分の乾燥を行い、粗化面形成用樹脂層２ａを形成した。
さらに、この粗化面形成用樹脂層２ａの上に上記Ａの粗化面形成用樹脂組成物（粘度：７Ｐａ・ｓ）をロールコータを用いて塗布し、水平状態で２０分間放置してから、６０℃で３０分の乾燥を行い、粗化面形成用樹脂層２ｂを形成し、厚さ３５μｍの粗化面形成用樹脂層を形成した（図７（ｂ）参照）。
【０２１５】
（７）上記（６）で粗化面形成用樹脂層を形成した基板１の両面に、直径８５μｍの黒円が印刷されたフォトマスクフィルムを密着させ、超高圧水銀灯により５００ｍＪ／ｃｍ² 強度で露光した後、ＤＭＤＧ溶液でスプレー現像した。この後、さらに、この基板を超高圧水銀灯により３０００ｍＪ／ｃｍ² 強度で露光し、１００℃で１時間、１２０℃で１時間、１５０℃で３時間の加熱処理を施し、フォトマスクフィルムに相当する寸法精度に優れた直径８５μｍのバイアホール用開口６を有する厚さ３５μｍの層間樹脂絶縁層２を形成した（図７（ｃ）参照）。
【０２１６】
（８）バイアホール用開口６を形成した基板を、８００ｇ／ｌのクロム酸を含む７０℃の溶液に１９分間浸漬し、層間樹脂絶縁層２の表面に存在するエポキシ樹脂粒子を溶解除去することにより、層間樹脂絶縁層２の表面を粗面（深さ３μｍ）とした（図７（ｄ）参照）。
【０２１７】
（９）次に、上記処理を終えた基板を、中和溶液（シプレイ社製）に浸漬してから水洗いした。
さらに、粗面化処理した該基板の表面に、パラジウム触媒（アトテック製）を付与することにより、層間樹脂絶縁層２の表面およびバイアホール用開口６の内壁面に触媒核を付着させた（図示せず）。
【０２１８】
（１０）次に、以下の組成の無電解めっき用前処理液中に基板を浸漬することにより前処理を施した。
〔無電解めっき用前処理液〕
ＮａＯＨ ０．１０ｍｏｌ／ｌ
ＨＣＨＯ ０．１０ｍｏｌ／ｌ
〔前処理条件〕
浸漬温度 ３０℃
液温度 ３分
【０２１９】
（１１）次に、以下の組成の無電解銅めっき水溶液中に、前処理を施した基板を浸漬して、粗面全体に厚さ０．６〜３．０μｍの無電解銅めっき膜１２を形成し、バイアホール用開口の内壁を含む層間樹脂絶縁層の表面に無電解銅めっき膜１２が形成された基板を得た（図８（ａ）参照）。
〔無電解めっき水溶液〕
ＮｉＳＯ₄ ０．００３ ｍｏｌ／ｌ
酒石酸 ０．２００ ｍｏｌ／ｌ
硫酸銅 ０．０３０ ｍｏｌ／ｌ
ＨＣＨＯ ０．０５０ ｍｏｌ／ｌ
ＮａＯＨ ０．１００ ｍｏｌ／ｌ
α、α′−ビピリジル １００ ｍｇ／ｌ
ポリエチレングリコール（ＰＥＧ） ０．１０ ｇ／ｌ
〔無電解めっき条件〕
３４℃の液温度で４０分
【０２２０】
（１２）市販の感光性ドライフィルムを無電解銅めっき層１２に貼り付け、マスクを載置して、１００ｍＪ／ｃｍ² で露光し、０．８％炭酸ナトリウム水溶液で現像処理することにより、厚さ２５μｍのめっきレジスト３を設けた（図８（ｂ）参照）。
【０２２１】
（１３）ついで、基板を５０℃の水で洗浄して脱脂し、２５℃の水で水洗後、さらに硫酸で洗浄してから、以下の条件で電解めっきを施し、めっきレジスト３非形成部に、厚さ２０μｍの電解銅めっき膜１３を形成した（図８（ｃ）参照）。
〔電解めっき液〕
硫酸 ２．２４ ｍｏｌ／ｌ
硫酸銅 ０．２６ ｍｏｌ／ｌ
添加剤 １９．５ ｍｌ／ｌ
（アトテックジャパン社製、カパラシドＧＬ）
〔電解めっき条件〕
電流密度 １ Ａ／ｄｍ²
時間 ６５ 分
温度 ２２±２ ℃
【０２２２】
（１４）さらに、めっきレジスト３を５％ＫＯＨで剥離除去した後、そのめっきレジスト３下の無電解めっき膜を硫酸と過酸化水素との混合液でエッチング処理して溶解除去し、独立の上層導体回路５（バイアホール７を含む）とした（図８（ｄ）参照）。
【０２２３】
（１５）ついで、上記（５）と同様の処理を行い、導体回路表面に粗化面を形成した（図９（ａ）参照）。
（１６）上記（６）〜（１５）の工程を繰り返すことにより、さらに上層の導体回路を形成し、多層配線板を得た（図９（ｂ）〜図１０（ｂ）参照）。
【０２２４】
（１７）次に、実施例１の（１７）〜（２０）と同様にして、はんだバンプ１７を有する多層プリント配線板を製造した（図１０（ｃ）参照）。
【０２２５】
（比較例１）
無電解めっき用前処理液として、以下の組成の無電解めっき用前処理液を用いた以外は、実施例１と同様にして多層プリント配線板を製造した。
〔無電解めっき用前処理液〕
ＮａＯＨ ０．００５ｍｏｌ／ｌ
ＨＣＨＯ ０．１０ｍｏｌ／ｌ
【０２２６】
（比較例２）
無電解めっき用前処理液として、以下の組成の無電解めっき用前処理液を用いた以外は、実施例１と同様にして多層プリント配線板を製造した。
〔無電解めっき用前処理液〕
ＮａＯＨ ０．３０ｍｏｌ／ｌ
ＨＣＨＯ ０．１０ｍｏｌ／ｌ
【０２２７】
（比較例３）
無電解めっき用前処理液として、以下の組成の無電解めっき用前処理液を用いた以外は、実施例１と同様にして多層プリント配線板を製造した。
〔無電解めっき用前処理液〕
ＮａＯＨ ０．１０ｍｏｌ／ｌ
ＨＣＨＯ ０．０５ｍｏｌ／ｌ
【０２２８】
実施例１〜５および比較例１〜３で得られた多層プリント配線板において、無電解めっき膜の形状、および、無電解めっき膜のピール強度について評価を行った。結果を表１に示した。なお、無電解めっき膜の形状は、下記の評価方法により評価した。
また、上記多層プリント配線板について、導通試験を行い、断線の有無を評価した。結果を表１に示した。
【０２２９】
（１）無電解めっき膜の形状
多層プリント配線板をバイアホールを含むように縦に切断し、無電解めっき膜の形状を顕微鏡により観察し、以下の評価基準で評価した。
評価基準
○．無電解めっき膜の未析出部分がなく、厚さが均一である。
×．無電解めっき膜の未析出部分が存在したり、厚さにバラツキが生じたりしている。
【０２３０】
【表１】

【０２３１】
表１に示したように、本発明の無電解めっき用前処理液を用いて製造した多層プリント配線板（実施例１〜５）では、層間樹脂絶縁層の表面全体に、厚さの均一な無電解めっき膜が形成されており、この無電解めっき膜のピール強度は０．８ｋｇ／ｃｍ以上と充分に高く、また、得られた多層プリント配線板は、接続性も良好であった。
一方、比較例１〜３の多層プリント配線板は、層間樹脂絶縁層の表面全体に、厚さの均一な無電解めっき膜が形成されておらず、めっき膜の未析出部分や、厚さの不均一な部分が見られた。また、この無電解めっき膜のピール強度は０．７ｋｇ／ｃｍ以下と無電解めっき膜の密着性は充分でなく、また、得られた多層プリント配線板は一部に接続不良がみられ、その接続性は、実施例と比べて低かった。
【０２３２】
【発明の効果】
以上説明してきたように、本発明の無電解めっき用前処理液は、上述の構成からなるため、該無電解めっき用前処理液を用いて前処理を施した後、無電解めっき処理を施した際に、被めっき物の表面に均一で、密着性に優れる無電解めっき膜を形成することができる。
また、本発明の無電解めっき用処理液は、上述の構成からなるため、樹脂からなる被めっき物の表面に、均一で、密着性に優れた無電解めっき膜を形成する際に用いる処理液として適している。
【０２３３】
また、第一〜第四の本発明の多層プリント配線板の製造方法は、上述の構成からなるため、基板や層間樹脂絶縁層と導体回路との密着性が優れ、信頼性、電気特性に優れた多層プリント配線板を製造することができる。
【図面の簡単な説明】
【図１】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図２】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図３】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図４】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図５】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図６】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図７】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図８】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図９】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【図１０】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造方法の工程の一部を示す断面図である。
【符号の説明】
１ 絶縁性基板
２ 層間樹脂絶縁層
３ めっきレジスト
４ 下層導体回路
４ａ 粗化面
５ 導体回路
６ バイアホール用開口
７ バイアホール
８ 銅箔
９ スルーホール
９ａ 粗化面
１０ 樹脂充填材
１２ 無電解銅めっき膜
１３ 電解銅めっき膜
１４ ソルダーレジスト層
１５ ニッケルめっき膜
１６ 金めっき膜
１７ はんだバンプ
１８ 貫通孔
１９ はんだ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pretreatment solution for electroless plating, a treatment solution for electroless plating obtained by combining the pretreatment solution for electroless plating and an electroless plating solution, and a method for producing a multilayer printed wiring board.
[0002]
[Prior art]
In recent years, so-called build-up multilayer wiring boards have attracted attention because of demands for higher density of multilayer wiring boards. This build-up multilayer wiring board is manufactured, for example, by a method as disclosed in Japanese Patent Publication No. 4-55555. That is, an interlayer resin having openings for via holes is formed by applying an electroless plating adhesive made of a photosensitive resin on a core substrate on which a lower conductor circuit is formed, and drying and exposing and developing it. An insulating layer is formed. Next, the surface of the interlayer resin insulation layer is roughened by a treatment with an oxidizing agent or the like, and then the photosensitive resin layer is exposed and developed to provide a plating resist. A conductor circuit pattern including a via hole is formed by plating or the like. Then, by repeating such a process a plurality of times, a multilayered build-up wiring board is manufactured.
[0003]
In addition, as electroless plating used for forming a conductor circuit of such a build-up multilayer wiring board, those using EDTA as a complexing agent are mainly used. For example, JP-A 63-158156 An example in which a conductor circuit is formed using such an electroless plating solution is described in the examples of Japanese Utility Model Laid-Open No. 2-188992 (US Pat. No. 5,055,321 and US Pat. No. 5,519,177). Yes.
[0004]
[Problems to be solved by the invention]
However, in such electroless plating solutions using EDTA as a complexing agent, there is a problem that compressive stress (force to spread) is generated in the deposited plating film and the plating film is peeled off from the resin insulating layer. It was seen.
This is because when forming a plating film, hydrogen is taken into the plating film, and this hydrogen serves as a stress generation source to generate compressive stress.
There was also a problem that plating did not precipitate in fine via holes having a diameter of 80 μm or less.
[0005]
Therefore, the present inventors have found that when tartaric acid is used as a complexing agent, the incorporation of hydrogen into the plating film is suppressed, and a plating film that is less likely to generate compressive stress can be formed. And an electroless plating solution comprising an aqueous solution containing an alkaline compound, a reducing agent, copper ions, and tartaric acid or a salt thereof.
[0006]
However, when an electroless plating film is formed on the surface of the substrate or the interlayer resin insulation layer using this electroless plating solution, a portion where the plating film is insufficiently deposited or an undeposited portion may be produced. Such a phenomenon was often observed near the opening for the via hole.
This is because the activation of the catalyst applied when forming the electroless plating film is insufficient, or the catalyst loses its activity after applying the catalyst and before performing the electroless plating treatment. It is thought that.
[0007]
In addition, in order to form an electroless plating film that is uniform and excellent in adhesiveness, a pretreatment is usually performed on an object to be plated before the electroless plating treatment.
Techniques for performing such pretreatment are disclosed in, for example, WO96 / 20294, JP-A-7-278823, JP-A-6-299360, and the like.
[0008]
WO96 / 20294 discloses a pretreatment solution for electroless plating comprising a pH adjuster, a reducing agent and a complexing agent. This pretreatment liquid for electroless plating stabilizes the deposition property of the plating film by adjusting the surface potential of the metal film.
Therefore, when an electroless plating film is formed on a metal film, an electroless plating film having a uniform and excellent adhesion can be formed, but the electroless plating film is formed on the resin surface of the substrate or the interlayer resin insulating layer. When the film was formed, a uniform electroless plating film was not formed, and the above problem could not be solved.
[0009]
Japanese Patent Application Laid-Open No. 7-278823 discloses a method of treating the surface of a metal object with an alkaline aqueous solution. According to the said method, the thin film of hydroxide is formed in the to-be-plated object surface, and the effect that the adhesiveness of a plating film improves by this is described.
However, after the surface of the interlayer resin insulation layer or the like is treated with the pretreatment liquid disclosed herein, a non-aqueous solution comprising the above-described alkaline compound, reducing agent, copper ion, and tartaric acid or a salt thereof is used. Although an electroless plating film was formed using an electrolytic plating solution, a uniform plating film was not formed, and the above problem could not be solved.
[0010]
The present invention has been made to solve the above-described problems, and its main purpose is to use it for pretreatment of an object to be plated, so that the surface of the interlayer resin insulating layer including the wall surface of the via hole opening is used. An object of the present invention is to provide a pretreatment solution for electroless plating that can form an electroless plating that is uniform and excellent in adhesion.
[0011]
Another object of the present invention is to provide a treatment solution for electroless plating using the pretreatment solution for electroless plating.
Furthermore, another object of the present invention is to provide a method for producing a multilayer printed wiring board using the pretreatment liquid for electroless plating or the treatment liquid for electroless plating.
[0012]
[Means for Solving the Problems]
As a result of intensive studies aimed at realizing the above object, the present inventors have electrolyzed an aqueous solution containing 0.01 to 0.25 mol / l of an alkaline compound and 0.1 to 0.3 mol / l of a reducing agent. By using it as a pretreatment liquid for plating, when a subsequent electroless plating treatment is performed, a plating film is uniformly deposited on the surface of the object to be plated, and the formed plating film is in close contact with the object to be plated. The present invention has been found to be excellent in performance, and has arrived at an invention having the following contents as a summary.
[0013]
That is, the pretreatment liquid for electroless plating of the present invention comprises an aqueous solution containing 0.01 to 0.25 mol / l alkaline compound and 0.1 to 0.3 mol / l reducing agent. To do.
[0014]
Moreover, it is desirable that the pretreatment liquid for electroless plating does not contain metal ions in the aqueous solution.
[0015]
The electroless plating treatment liquid of the present invention includes an electroless plating pretreatment liquid of the present invention and an electroless plating liquid comprising an alkaline compound, a reducing agent, copper ions, and an aqueous solution containing tartaric acid or a salt thereof.
It is characterized by comprising a combination of
[0016]
In the electroless plating treatment solution, the electroless plating solution is preferably an aqueous solution containing at least one metal ion selected from the group consisting of nickel ions, cobalt ions, and iron ions.
In the electroless plating treatment solution, the concentration of the alkaline compound is 0.025 to 0.25 mol / l, and the concentration of the reducing agent is 0.03 to 0.15 mol / l. The concentration of the copper ion is preferably 0.02 to 0.06 mol / l, and the concentration of tartaric acid or a salt thereof is preferably 0.05 to 0.3 mol / l.
[0017]
Further, in the method for producing a multilayer printed wiring board according to the first aspect of the present invention, a multilayer printed wiring in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate and these conductor circuits are connected through via holes. A method of manufacturing a board,
It includes at least the following steps (A) to (F).
(A) A step of applying a catalyst to the surface of the substrate or the interlayer resin insulation layer,
(B) A step of performing pretreatment on the substrate or the interlayer resin insulation layer provided with the catalyst using the pretreatment liquid for electroless plating of the present invention,
(C) forming an electroless plating film on the substrate or the interlayer resin insulation layer;
(D) forming a plating resist on a part of the electroless plating film;
(E) forming an electrolytic plating film on the plating resist non-forming portion; and
(F) A step of removing the electroless plating film under the plating resist after removing the plating resist.
[0018]
The liquid temperature of the pretreatment liquid for electroless plating in the step (B) of the method for producing a multilayer printed wiring board according to the first aspect of the present invention is preferably 20 to 50 ° C., and the pretreatment in this step The time is desirably 0.5 to 5 minutes.
[0019]
In addition, in the method for producing a multilayer printed wiring board according to the second aspect of the present invention, a multilayer printed wiring comprising a conductor circuit and an interlayer resin insulating layer sequentially laminated on a substrate, and these conductor circuits are connected via via holes. A method of manufacturing a board,
It includes at least the following steps (a) to (f).
(A) providing a catalyst on the surface of the substrate or the interlayer resin insulation layer;
(B) a step of performing pretreatment on the substrate or the interlayer resin insulation layer provided with the catalyst, using the pretreatment liquid for electroless plating according to the present invention;
(C) forming an electroless plating film on the substrate or the interlayer resin insulation layer;
(D) forming an electrolytic plating film on the electroless plating film;
(E) forming an etching resist on a portion of the electrolytic plating film; and
(F) A step of removing the electrolytic plating film and the electroless plating film under the etching resist non-forming portion by an etching process.
[0020]
The temperature of the pretreatment liquid for electroless plating in the step (B) of the method for producing a multilayer printed wiring board of the second invention is preferably 20 to 50 ° C., and the pretreatment in this step The time is desirably 0.5 to 5 minutes.
[0021]
Further, in the method for producing a multilayer printed wiring board according to the third aspect of the present invention, a multilayer printed wiring comprising a conductor circuit and an interlayer resin insulating layer sequentially laminated on a substrate, and these conductor circuits are connected via via holes. A method of manufacturing a board,
It includes at least the following steps (A) to (E).
(A) A step of applying a catalyst to the surface of the substrate or the interlayer resin insulation layer,
(B) The substrate or the interlayer resin insulation layer provided with the catalyst is pretreated using the treatment solution for electroless plating of the present invention, and then the substrate or the interlayer resin insulation layer is coated on the substrate or the interlayer resin insulation layer. Forming an electrolytic plating film;
(C) forming a plating resist on a part of the electroless plating film;
(D) forming an electrolytic plating film on the plating resist non-forming portion; and
(E) A step of removing the electroless plating film under the plating resist after removing the plating resist.
[0022]
The liquid temperature of the pretreatment liquid for electroless plating in the step (B) of the method for producing a multilayer printed wiring board of the third aspect of the present invention is preferably 20 to 50 ° C., and the pretreatment in this step The time is desirably 0.5 to 5 minutes.
[0023]
According to a fourth aspect of the present invention, there is provided a multilayer printed wiring board manufacturing method in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate, and these conductor circuits are connected via via holes. A method of manufacturing a board,
It includes at least the following steps (a) to (e).
(A) providing a catalyst on the surface of the substrate or the interlayer resin insulation layer;
(B) The substrate or the interlayer resin insulation layer provided with the catalyst is pretreated using the treatment liquid for electroless plating of the present invention, and then applied to the substrate or the interlayer resin insulation layer. Forming an electrolytic plating film;
(C) forming an electrolytic plating film on the electroless plating film;
(D) forming an etching resist on a portion of the electrolytic plating film; and
(E) A step of removing the electrolytic plating film and the electroless plating film under the etching resist non-forming portion by an etching process.
[0024]
The liquid temperature of the pretreatment liquid for electroless plating in the step (B) of the method for producing a multilayer printed wiring board according to the fourth aspect of the present invention is preferably 20 to 50 ° C., and the pretreatment in this step The time is desirably 0.5 to 5 minutes.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The pretreatment liquid for electroless plating of the present invention is characterized by comprising an aqueous solution containing 0.01 to 0.25 mol / l alkaline compound and 0.1 to 0.3 mol / l reducing agent.
[0026]
Since the pretreatment liquid for electroless plating comprises an aqueous solution containing 0.01 to 0.25 mol / l of an alkaline compound and 0.1 to 0.3 mol / l of a reducing agent, before the electroless plating, By using the treatment liquid for pretreatment of the object to be plated, it is possible to form an electroless plating film that is uniform and excellent in adhesion on the surface of the object to be plated during electroless plating.
[0027]
Usually, in the electroless plating treatment, it is necessary to previously apply a catalyst to the surface of the object to be plated. For example, after depositing palladium metal or the like on the surface of the object to be plated as the catalyst, the electroless plating treatment is performed. However, the palladium deposited on the surface of the object to be plated in this manner is oxidized when left in the air or water and loses its activity as a catalyst.
However, after the catalyst is applied to the surface of the object to be plated, the catalyst that has been oxidized and lost its activity is reduced again by pretreatment using the pretreatment liquid for electroless plating, and the activity as a catalyst is reduced. You can get it back.
[0028]
Examples of the alkaline compound include potassium hydroxide, sodium hydroxide, lithium hydroxide, calcium hydroxide and the like.
In addition, when the concentration of these alkaline compounds is less than 0.01 mol / l, the pH of the pretreatment liquid for electroless plating may be low, and the reducing action by the reducing agent may be insufficient. If it exceeds 0.25 mol / l, the reducing agent may be decomposed, so the concentration of the alkaline compound is limited to the above range.
[0029]
Examples of the reducing agent include sodium hypophosphite, aldehyde, borohydride, hydrazine and the like.
In addition, when the concentration of these reducing agents is less than 0.1 mol / l, there is almost no reducing action. On the other hand, even when the concentration of the reducing agent exceeds 0.3 mol / l, the reducing action remains almost unchanged, Since it is only economically disadvantageous, the concentration of the reducing agent is limited to the above range.
[0030]
The pretreatment liquid for electroless plating preferably contains no metal ions or complexing agents in the aqueous solution.
When a metal ion or a complexing agent is contained, an activated catalyst on the surface of the object to be plated is obtained when the surface of the object to be plated is pretreated using the pretreatment liquid for electroless plating. Reacts with metal ions and the like, and the number of catalysts that are insufficiently activated increases. In this case, the initial reactivity during the electroless plating process is suppressed, and the plating film is not uniformly deposited.
[0031]
The reason for this will be described taking the case of using palladium as a catalyst as an example.
That is, when the object to be plated is immersed in a solution containing palladium chloride, for example, palladium ions are reduced by other metal ions and deposited as palladium metal on the surface of the object to be plated, and this palladium metal serves as a catalyst. It will have the activity of.
Here, when palladium metal is oxidized, the activity as a catalyst is lost. As a result, the proportion of palladium metal having activity as a catalyst is reduced, which leads to a decrease in initial reactivity during plating, so that the plating film is not uniformly deposited on the surface of the object to be plated.
[0032]
In the present invention, after the catalyst is applied to the object to be plated, the pretreatment is performed using the pretreatment liquid for electroless plating of the present invention, so that the catalyst can be sufficiently activated by this pretreatment, and as a result By performing the electroless plating treatment, a uniform electroless plating film having excellent adhesion can be formed.
[0033]
Next, the treatment solution for electroless plating of the present invention will be described.
The electroless plating treatment solution is a combination of the electroless plating pretreatment solution of the present invention and an electroless plating solution comprising an alkaline compound, a reducing agent, copper ions, and an aqueous solution containing tartaric acid or a salt thereof. It is characterized by that.
[0034]
The treatment liquid for electroless plating is suitable as a treatment liquid used for forming a uniform electroless plating film having excellent adhesion on the surface of an object to be plated made of resin. This can sufficiently activate the catalyst applied to the surface of the object to be plated by the pretreatment liquid for electroless plating, and the plating film formed by the electroless plating liquid has a hydrogen uptake amount. This is because it has little tensile strength.
[0035]
In the electroless plating solution of the electroless plating treatment solution, examples of the alkaline compound include sodium hydroxide, potassium hydroxide, and ammonia.
The concentration is preferably 0.025 to 0.25 mol / l.
By adjusting the concentration of the alkaline compound within the above range, the plating deposition rate can be reduced to 1 to 2 μm / hour, so that a uniform electroless plating film can be formed on the surface of the object to be plated. In particular, even when the object to be plated has a through hole or a non-through hole with a small opening diameter, an electroless plating film that is uniform on the wall surface of the through hole or the non-through hole and has excellent adhesion. Can be formed.
[0036]
Examples of the reducing agent include formaldehyde, sodium hypophosphite, NaBH._Four , Hydrazine and the like.
The concentration is preferably 0.03 to 0.15 mol / l.
This is because the plating deposition rate can be reduced to 1 to 2 μm / hour by adjusting the concentration of the reducing agent within the above range.
[0037]
Examples of the compound for forming the copper ion include copper sulfate and copper chloride.
Moreover, as for the density | concentration, it is desirable that it is 0.02-0.06 mol / l in the density | concentration of a copper ion.
By adjusting the copper ion concentration to the above range, even if the object to be plated has a through hole or a non-through hole with a small opening diameter, it is uniform and adheres to the wall surface of the through hole or the non-through hole. It is possible to form an electroless plating film that is excellent in resistance.
[0038]
Examples of the salt of tartaric acid include sodium salt and potassium salt, and these salts may be salts in which only one of two carboxyl groups is substituted with the metal. Each of them may be a salt substituted with the above metal.
The concentration is preferably 0.05 to 0.3 mol / l.
By adjusting the concentration of tartaric acid or a salt thereof within the above range, an electroless plating film that is particularly excellent in adhesion to an object to be plated can be formed.
[0039]
Further, the electroless plating solution preferably further contains at least one metal ion selected from the group consisting of nickel ions, cobalt ions, and iron ions.
This is because the generation of hydrogen is suppressed, and as a result, an appropriate tensile stress is generated in the plating film and adheres to the substrate, so that the plating film hardly peels off.
[0040]
Examples of the compound for forming the nickel ion include nickel chloride and nickel sulfate. Examples of the compound for forming the cobalt ion include cobalt chloride and the like to form the iron ion. As a compound for doing, iron chloride etc. are mentioned, for example.
[0041]
Next, the manufacturing method of the multilayer printed wiring board of 1st this invention is demonstrated.
According to a first aspect of the present invention, there is provided a method for producing a multilayer printed wiring board comprising: a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate; and the conductor circuits are connected via via holes. A manufacturing method,
It includes at least the following steps (A) to (F).
(A) A step of applying a catalyst to the surface of the substrate or the interlayer resin insulation layer,
(B) A step of performing pretreatment on the substrate or the interlayer resin insulation layer provided with the catalyst using the pretreatment liquid for electroless plating of the present invention,
(C) forming an electroless plating film on the substrate or the interlayer resin insulation layer;
(D) forming a plating resist on a part of the electroless plating film;
(E) forming an electrolytic plating film on the plating resist non-forming portion; and
(F) A step of removing the electroless plating film under the plating resist after removing the plating resist.
[0042]
According to the first method for producing a multilayer printed wiring board of the present invention, the surface of the substrate or the interlayer resin insulation layer is subjected to pretreatment using the pretreatment liquid for electroless plating of the present invention, and then electroless plating is performed. Since the conductor circuit is formed by processing, electrolytic plating, etc., the adhesion between the substrate and the interlayer resin insulation layer and the conductor circuit is excellent, producing a multilayer printed wiring board with excellent reliability and electrical characteristics can do.
[0043]
Here, first, the steps (A) to (F), that is, the step of forming a conductor circuit on the substrate or the interlayer insulating layer will be described, and all the manufacturing steps for manufacturing a multilayer printed wiring board will be described. This will be described later.
[0044]
In the method for producing a multilayer printed wiring board according to the first aspect of the present invention, a catalyst is applied to the surface of the substrate or the interlayer resin insulation layer.
As said catalyst, palladium metal etc. are mentioned, for example, This palladium metal can be provided by the following method, for example.
The materials for the substrate and the interlayer resin insulation layer will be described in detail later.
[0045]
Further, it is desirable to form a roughened surface on the surface of the substrate or the interlayer resin insulation layer in advance before applying the catalyst. This is because the adhesion to the electroless plating film formed in the subsequent process can be improved.
In addition, when the roughened surface is formed, the electroless plating film formed on the roughened surface is formed by tracing the unevenness of the roughened surface. The electroless plating film is relatively thicker than the above, and has the following advantages.
[0046]
That is, after the electroless plating film is formed, a plating resist is provided, and then electrolytic plating is performed to form a thick plating film, and the plating resist is removed and the electroless plating film under the plating resist is removed by etching. In the additive method, it is easier to etch the electroless plating film in the concave portion that is relatively thinner than the convex portion, and the entire plating film can be easily removed completely by this etching, so that an etching residue is not generated. In addition, the insulation reliability between the formed circuits is excellent.
[0047]
In the case of using palladium metal as the catalyst, the catalyst can be imparted by using, for example, the following method.
That is, a substrate or a wiring board (hereinafter also referred to as an interlayer resin insulating layer forming wiring board) in which a conductor circuit and an interlayer resin insulating layer are laminated on each of the substrates is formed of palladium chloride (PbCl₂ ) And stannous chloride (SnCl)₂ The catalyst can be applied by precipitating palladium ions as palladium metal on the surface of the substrate or the interlayer resin insulation layer-formed wiring board by the reducing power of stannous ions. .
[0048]
Next, the substrate to which the catalyst is applied or the interlayer resin insulating layer is pretreated using the pretreatment liquid for electroless plating of the present invention.
The pretreatment is performed by immersing the substrate or the interlayer resin insulation layer-formed wiring board in the pretreatment liquid for electroless plating.
[0049]
At this time, the temperature of the pretreatment liquid for electroless plating is desirably 20 to 50 ° C.
If the temperature of the pretreatment liquid for electroless plating is less than 20 ° C., the catalyst applied in the previous step cannot be sufficiently reduced, and the proportion of unreduced catalyst increases. On the other hand, if the liquid temperature exceeds 50 ° C., the reducing agent tends to deteriorate and the reactivity during plating hardly improves, which is economically disadvantageous.
A more desirable liquid temperature is 25 to 40 ° C.
[0050]
The immersion time in the pretreatment liquid for electroless plating, that is, the pretreatment time is preferably 0.5 to 5 minutes.
When the pretreatment time is less than 0.5 minutes, the catalyst applied in the previous step may not be sufficiently reduced. On the other hand, even when the pretreatment time exceeds 5 minutes, the reactivity during plating is almost zero. It is because it does not improve.
[0051]
Next, an electroless plating film is formed on the pretreated substrate or interlayer resin layer.
The electroless plating film can be formed by immersing a substrate or an interlayer resin insulation layer-formed wiring board in an electroless plating solution.
The electroless plating solution used here is not particularly limited, and conventionally known electroless plating solutions can be used in addition to the above-described electroless plating solutions.
[0052]
Next, a plating resist is formed on a part of the electroless plating film, that is, a part corresponding to the conductor circuit non-forming part.
The plating resist can be formed, for example, by applying a photosensitive dry film or applying a liquid resist and then performing an exposure development process.
[0053]
Further, an electrolytic plating film is formed on the plating resist non-forming portion.
The electrolytic plating film can be formed by using the already formed electroless plating film as a plating lead.
Specifically, for example, an electrolytic copper plating film can be formed by using an electrolytic plating solution containing sulfuric acid, copper sulfate and an additive.
[0054]
Next, the plating resist is removed, and thereafter, the electroless plating film existing under the plating resist is removed by an etching process.
Here, as an etching solution used for removing the electroless plating film, for example, a sulfuric acid-hydrogen peroxide aqueous solution, an aqueous solution of persulfate such as ammonium persulfate or potassium persulfate, an aqueous solution of ferric chloride, cupric chloride, etc. Hydrochloric acid, nitric acid, hot dilute sulfuric acid and the like.
Moreover, the etching liquid containing a cupric complex and an organic acid can also be used.
[0055]
Moreover, you may remove the catalyst provided to the surface of a board | substrate or an interlayer resin insulation layer using an acid and an oxidizing agent as needed. By removing the catalyst, the metal such as palladium used for the catalyst is eliminated, so that deterioration of electrical characteristics can be prevented.
[0056]
Through these steps, a conductor circuit can be formed on the substrate or the interlayer resin insulation layer.
Further, in the first method for producing a multilayer printed wiring board of the present invention, before forming the electroless plating film, the surface of the substrate or the interlayer resin insulation layer is formed using the pretreatment liquid for electroless plating of the present invention. Since the pretreatment has been performed, a conductor circuit having excellent adhesion to the substrate and the interlayer resin insulation layer can be formed.
[0057]
Next, all the manufacturing processes of the manufacturing method of the 1st multilayer printed wiring board of this invention are demonstrated in process order.
(1) In the first method for producing a multilayer printed wiring board of the present invention, first, a conductor circuit is formed on a substrate.
The conductor circuit can be formed by the method described above.
The substrate is preferably a resin substrate, and specific examples include a glass epoxy substrate, a polyester substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a thermosetting polyphenylene ether substrate, and a fluororesin substrate.
In addition, you may use what formed the conductor circuit by the etching process to the copper clad laminated board, the RCC board | substrate, etc.
[0058]
(2) When connecting between conductor circuits with a substrate sandwiched between them, first, through holes for through holes are provided in the insulating substrate using a laser, a drill, or the like.
As the laser, a carbon dioxide laser, a UV laser, an excimer laser, or the like can be used.
[0059]
Next, if necessary, the substrate surface including the wall surface of the through hole for the through hole is roughened, and then the substrate surface is pretreated by the above-described method, and the wall surface of the through hole and the surface of the copper foil, etc. Electroless plating is applied to form a through hole. As the electroless plating, copper plating is preferable.
[0060]
Thereafter, a plating resist is formed on a portion where the conductor circuit is not formed on the substrate, and a conductor circuit is formed by applying electrolytic plating to the portion where the plating resist is not formed.
An electrolytic plating film may also be formed on the electroless plating film formed on the wall surface of the through hole for the through hole.
Moreover, it is desirable to simultaneously form the conductor circuit on the substrate and the through hole. This is because the number of processes can be reduced and it is economically advantageous.
[0061]
(3) Next, if necessary, the inner wall of the through hole and the surface of the lower conductor circuit are roughened. Examples of the roughening treatment method include blackening (oxidation) -reduction treatment, etching treatment, treatment with Cu—Ni—P needle-shaped alloy plating, and the like.
[0062]
Specific examples of the blackening (oxidation) -reduction treatment include NaOH (10 to 20 g / l), NaClO.₂ (40-50 g / l), Na_Three PO_Four Blackening treatment using an aqueous solution containing (6-15 g / l) as a blackening bath (oxidation bath), and NaOH (2.7-10 g / l), NaBH_Four Examples include a method of performing a reduction treatment using an aqueous solution containing (1.0 to 6.0 g / l) as a reduction bath.
[0063]
As an etching solution used for the etching treatment, a mixed solution of an organic acid and a cupric complex is desirable. Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, benzoic acid, glycolic acid, Examples include lactic acid, malic acid, sulfamic acid and the like. These may be used alone or in combination of two or more. In the etching solution, the organic acid content is preferably 0.1 to 30% by weight. This is because the solubility of oxidized copper can be maintained and catalyst stability can be ensured.
[0064]
The cupric complex is preferably an azole cupric complex. This cupric complex of azoles acts as an oxidizing agent that oxidizes metallic copper and the like. Examples of azoles include diazole, triazole, and tetrazole. Among these, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-undecylimidazole are desirable. In the etching solution, the content of the cupric complex is preferably 1 to 15% by weight. This is because it is excellent in solubility and stability and can also dissolve noble metals such as Pd constituting the catalyst nucleus.
[0065]
Examples of the plating treatment include copper sulfate (1 to 40 g / l), nickel sulfate (0.1 to 6.0 g / l), citric acid (10 to 20 g / l), and sodium hypophosphite (10 to 10 g / l). 100 g / l), boric acid (10-40 g / l) and surfactant (manufactured by Nissin Chemical Industry Co., Surfinol 465) (0.01-10 g / l) in an electroless plating bath of pH = 9 And a method of forming a roughened layer made of a Cu-Ni-P alloy by electroless plating.
This is because the crystal structure of the plating film deposited in this range is a needle-like structure, which is excellent in anchor effect. In addition to the above compounds, complexing agents and additives may be added to the electroless plating bath.
[0066]
(4) When a through hole is formed after the above step, a resin filler is filled into the through hole. In addition, if necessary, the insulating substrate surface may be filled with a resin filler in a recess where the lower conductor circuit is not formed, and then the insulating substrate surface may be planarized by polishing or the like.
[0067]
(5) When a resin filler is filled in the through hole, the resin filler is dried under conditions of, for example, 100 ° C./20 minutes and then cured.
Curing is preferably performed at a temperature of 50 to 250 ° C. An example of the curing condition is a method of heating at 100 ° C. for 1 hour and then heating at 150 ° C. for 1 hour. As needed, you may perform step hardening which makes it harden | cure by changing high temperature and temperature from low temperature sequentially.
[0068]
When the surface of the conductor layer is flattened by polishing, the lower-layer conductor circuit may be roughened once more as necessary. Examples of the roughening treatment method include blackening (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, treatment with Cu—Ni—P alloy plating, and the like.
[0069]
(6) An uncured resin insulating layer made of a thermosetting resin or a resin composite is formed on the lower conductor circuit, or a resin layer made of a thermoplastic resin is formed.
The uncured resin insulation layer may be formed by applying uncured resin with a roll coater, curtain coater, or the like, or by thermocompression bonding of an uncured (semi-cured) resin film. Good. Furthermore, you may affix the resin film in which metal layers, such as copper foil, were formed in the single side | surface of an uncured resin film.
The resin layer made of a thermoplastic resin is preferably formed by thermocompression bonding a resin molded body formed into a film shape.
[0070]
In the case of applying the uncured resin, the resin is applied and then heat treatment is performed.
By performing the heat treatment, the uncured resin can be thermoset.
In addition, you may perform the said thermosetting, after forming the opening for via holes and a through-hole which are mentioned later.
[0071]
Further, when an interlayer resin insulation layer is formed by pasting the resin film, the formation of the interlayer resin insulation layer is performed by pressing the resin film under reduced pressure or under vacuum using an apparatus such as a vacuum laminator, This is done by thermosetting the resin film.
In addition, you may perform the said thermosetting, after forming the opening for via holes and a through-hole which are mentioned later.
[0072]
In addition, when a thermoplastic resin molded into a film is thermocompression bonded to a conductor circuit, the thermoplastic resin molded into a film under a reduced pressure or vacuum can be crimped using a device such as a vacuum laminator. Is desirable.
[0073]
Specific examples of the thermosetting resin include, for example, epoxy resins, phenol resins, polyimide resins, polyester resins, bismaleimide resins, polyolefin resins, polyphenylene ether resins, and the like.
[0074]
Examples of the epoxy resin include cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, biphenol F type epoxy resin, naphthalene type epoxy resin, Examples thereof include cyclopentadiene type epoxy resins, epoxidized products of condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group, triglycidyl isocyanurate, and alicyclic epoxy resins. These may be used alone or in combination of two or more. Thereby, it will be excellent in heat resistance.
[0075]
Examples of the polyolefin resin include polyethylene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, cycloolefin resin, and copolymers of these resins.
[0076]
Moreover, as a commercial item of the said polyolefin resin, Sumitomo 3M Co., Ltd. brand name: 1592 etc. are mentioned, for example. Moreover, as a commercial item of thermoplastic polyolefin-type resin whose melting | fusing point is 200 degreeC or more, the brand name: TPX (melting | fusing point 240 degreeC) made by Mitsui Petrochemical Industry Co., Ltd., the brand name made by Idemitsu Petrochemical Co., Ltd .: SPS ( Melting point of 270 ° C.).
Among these, the dielectric constant and dielectric loss tangent are low, and even when a high frequency signal in the GHz band is used, signal delay and signal error are not easily generated. Olefin resins are desirable.
[0077]
As the cycloolefin-based resin, a homopolymer or copolymer of a monomer composed of 2-norbornene, 5-ethylidene-2-norbornene, or a derivative thereof is desirable. Examples of the derivative include those in which an amino group for forming a bridge, a maleic anhydride residue, or a maleic acid-modified one is bonded to the cycloolefin such as 2-norbornene.
Examples of the monomer for synthesizing the copolymer include ethylene and propylene.
[0078]
The cycloolefin-based resin may be a mixture of two or more of the above-described resins, or may include a resin other than the cycloolefin-based resin.
Moreover, when the said cycloolefin resin is a copolymer, a block copolymer may be sufficient and a random copolymer may be sufficient.
[0079]
The cycloolefin resin is preferably a thermosetting cycloolefin resin. This is because by heating to form a crosslink, the rigidity becomes higher and the mechanical properties are improved.
The glass transition temperature (Tg) of the cycloolefin resin is preferably 130 to 200 ° C.
[0080]
The cycloolefin resin may be a resin sheet (film) that has already been molded, and a monomer or a low molecular weight polymer having a certain molecular weight is dispersed in a solvent such as xylene or cyclohexane. It may be in an uncured solution state.
In the case of a resin sheet, so-called RCC (RESIN COATED copper) may be used.
The cycloolefin-based resin may contain a flame retardant such as aluminum hydroxide, magnesium hydroxide, or phosphate ester.
[0081]
The polyolefin resin may contain an organic filler.
By including the organic filler, for example, when the via hole opening is formed by irradiating the interlayer resin insulating layer with laser light, the via hole opening having a desired shape can be satisfactorily formed.
[0082]
In other words, when an infrared laser such as a carbon dioxide laser is irradiated to form an opening for a via hole, the organic filler serves as a buffer against heat, and the generated heat and heat reflected from the conductor circuit are reduced. Absorb part. The organic filler serves as a mechanical reinforcing agent for maintaining the predetermined shape of the resin composition, and as a result, the shape of the surrounding resin can be maintained. For example, an opening can be formed.
[0083]
In addition, when forming an opening for a via hole or the like by irradiating with an ultraviolet laser, the organic filler absorbs the ultraviolet ray, and therefore, the interlayer resin insulating layer in the portion irradiated with the ultraviolet laser is decomposed and disappeared, which is the target. Shaped openings for via holes and the like can be formed.
[0084]
Therefore, when a via hole is formed by forming a via hole by irradiating the laser and forming a metal layer in this opening, the metal layer is in close contact with the lower conductor circuit and is not easily peeled off. The connectivity and reliability of the printed wiring board is improved.
[0085]
Although it does not specifically limit as said organic filler, For example, a melamine, a phenol resin, an epoxy resin, a polyimide resin, a fluororesin, PPO, PPE etc. are mentioned. These compounds may be used alone or in combination of two or more.
[0086]
The content of the organic filler is preferably 5 to 60% by weight. When the content of the organic filler is less than 5% by weight, the content of the organic filler is too small, so that the above-mentioned role cannot be performed when the laser beam is irradiated, and the intended shape for the via hole is used. In some cases, an opening or the like cannot be formed. On the other hand, when the content of the organic filler exceeds 60% by weight, the characteristics of the polyolefin resin are lost, and for example, the dielectric constant becomes too high. A more preferable content of the organic filler is 14 to 60% by weight.
[0087]
The shape of the organic filler is not particularly limited, and examples thereof include a spherical shape and a polyhedral shape. Among these, cracks are unlikely to occur, and even if stress is generated in the interlayer resin insulation layer due to heat or thermal shock. From the viewpoint that the stress is easily relieved, a spherical shape is preferable.
[0088]
The particle size of the organic filler is preferably 0.05 to 0.2 μm. If the particle size of the organic filler is less than 0.05 μm, the particle size is too small, so it may be difficult to uniformly mix the organic filler, while the particle size of the organic filler is 0.2 μm. If it exceeds 1, the particle size of the organic filler is too large, so that it may not be completely decomposed and removed when irradiated with laser light.
[0089]
When blending the organic filler, two or more kinds of organic fillers having different particle sizes may be blended. However, when too many organic fillers having different particle sizes are blended, the organic filler is likely to aggregate and agglomerate. Since the diameter of the product exceeds 0.2 μm and the same inconvenience as when using a material exceeding 0.2 μm may occur, when blending organic fillers having different diameters, only two types of blending are used. It is desirable.
[0090]
Examples of the polyphenylene ether resin include a thermoplastic polyphenylene ether resin having a repeating unit represented by the following chemical formula (1) and a thermosetting polyphenylene ether resin having a repeating unit represented by the following chemical formula (2). It is done.
[0091]
[Chemical 1]

[0092]
(In the formula, n represents an integer of 2 or more.)
[0093]
[Chemical 2]

[0094]
(In the formula, m represents an integer of 2 or more. Also, R¹ , R² Is a methylene group, ethylene group or -CH₂ -O-CH₂ -Represents that both may be the same or different. )
[0095]
Further, the thermoplastic polyphenylene ether resin having a repeating unit represented by the chemical formula (2) has a structure in which a methyl group is bonded to a benzene ring, but as a polyphenylene ether resin that can be used in the present invention, Further, a derivative in which the methyl group is substituted with another alkyl group such as an ethyl group, a derivative in which hydrogen of the methyl group is substituted with fluorine, or the like may be used.
[0096]
Examples of the thermoplastic resin include phenoxy resin, polyether sulfone, and polysulfone.
Further, these composites (resin composites) are not particularly limited as long as they contain a thermosetting resin and a thermoplastic resin, and specific examples thereof include, for example, a roughened surface-forming resin composition. Etc.
[0097]
Examples of the roughened surface-forming resin composition include, in an uncured heat-resistant resin matrix that is hardly soluble in a roughened liquid consisting of at least one selected from an acid, an alkali, and an oxidizing agent. And a material in which a substance soluble in a roughening liquid comprising at least one selected from oxidizing agents is dispersed.
As used herein, the terms “slightly soluble” and “soluble” refer to those having a relatively high dissolution rate as “soluble” for convenience when immersed in the same roughening solution for the same time. The slow one is called “slightly soluble” for convenience.
[0098]
The heat resistant resin matrix is preferably one that can maintain the shape of the roughened surface when the roughened surface is formed on the interlayer resin insulating layer using the roughening liquid, for example, a thermosetting resin, a thermoplastic resin. Examples thereof include resins and composites thereof. Further, by using a photosensitive resin, the via hole opening may be formed in the interlayer resin insulating layer by exposure and development processing.
[0099]
Examples of the thermosetting resin include an epoxy resin, a phenol resin, a polyimide resin, a polyolefin resin, and a fluororesin. Moreover, when sensitizing the said thermosetting resin, methacrylic acid, acrylic acid, etc. are used, and a thermosetting group is (meth) acrylated. In particular, (meth) acrylate of epoxy resin is desirable. Furthermore, an epoxy resin having two or more epoxy groups in one molecule is more desirable. Not only can the above-mentioned roughened surface be formed, but also has excellent heat resistance, etc., so that stress concentration does not occur in the conductor circuit even under heat cycle conditions, and the conductor circuit and the interlayer resin insulation layer Peeling hardly occurs between
[0100]
Examples of the thermoplastic resin include polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like. These may be used alone or in combination of two or more.
[0101]
The substance soluble in the roughening liquid consisting of at least one selected from the acid, alkali and oxidizing agent is at least one selected from inorganic particles, resin particles, metal particles, rubber particles, liquid phase resin and liquid phase rubber. It is desirable to be a seed.
[0102]
Examples of the inorganic particles include aluminum compounds, calcium compounds, potassium compounds, magnesium compounds, and silicon compounds. These may be used alone or in combination of two or more.
[0103]
Examples of the aluminum compound include alumina and aluminum hydroxide. Examples of the calcium compound include calcium carbonate and calcium hydroxide. Examples of the potassium compound include potassium carbonate. Examples of the magnesium compound include magnesia, dolomite, basic magnesium carbonate, and talc. Examples of the silicon compound include silica and zeolite. These may be used alone or in combination of two or more.
[0104]
The alumina particles can be dissolved and removed with hydrofluoric acid, and calcium carbonate can be dissolved and removed with hydrochloric acid. Sodium-containing silica and dolomite can be dissolved and removed with an alkaline aqueous solution.
[0105]
Examples of the resin particles include those made of a thermosetting resin, a thermoplastic resin, and the like. When the resin particles are immersed in a roughening solution made of at least one selected from an acid, an alkali, and an oxidizing agent, the heat resistance It is not particularly limited as long as it has a faster dissolution rate than the resin matrix. Specifically, for example, amino resins (melamine resins, urea resins, guanamine resins, etc.), epoxy resins, phenol resins, phenoxy resins, polyimide resins, Examples include polyphenylene resin, polyolefin resin, fluororesin, and bismaleimide-triazine resin. These may be used alone or in combination of two or more.
[0106]
In addition, the said epoxy resin can be arbitrarily manufactured by selecting what kind of oligomer and hardening | curing agent what melt | dissolves in an acid and an oxidizing agent, and a thing hardly soluble in these. For example, a resin obtained by curing a bisphenol A type epoxy resin with an amine curing agent dissolves very well in chromic acid, but a resin obtained by curing a cresol novolac type epoxy resin with an imidazole curing agent is difficult to dissolve in chromic acid. .
[0107]
The resin particles must be previously cured. If not cured, the resin particles are dissolved in a solvent that dissolves the resin matrix, so they are uniformly mixed, and only the resin particles cannot be selectively dissolved and removed with an acid or an oxidizing agent. is there.
[0108]
Examples of the metal particles include gold, silver, copper, tin, zinc, stainless steel, aluminum, nickel, iron, lead, and the like. These may be used alone or in combination of two or more.
In addition, the metal particles may be coated with a resin or the like in order to ensure insulation.
[0109]
Examples of the rubber particles include acrylonitrile-butadiene rubber, polychloroprene rubber, polyisoprene rubber, acrylic rubber, polysulfuric rigid rubber, fluorine rubber, urethane rubber, silicone rubber, ABS resin, and the like.
[0110]
In addition, as the rubber particles, for example, polybutadiene rubber, various modified polybutadiene rubbers such as epoxy modification, urethane modification, (meth) acrylonitrile modification, (meth) acrylonitrile / butadiene rubber containing a carboxyl group, and the like can be used. By using these rubber particles, the rubber particles are easily dissolved in an acid or an oxidizing agent. That is, when dissolving rubber particles using an acid, an acid other than a strong acid can be dissolved. When dissolving rubber particles using an oxidizing agent, even permanganic acid having a relatively low oxidizing power can be used. Can be dissolved. Even when chromic acid is used, it can be dissolved at a low concentration. Therefore, no acid or oxidant remains on the surface of the interlayer resin insulation layer, and as described later, after forming a roughened surface, when a catalyst such as palladium chloride is applied, the catalyst is not applied, or the catalyst Is not oxidized. These may be used alone or in combination of two or more.
[0111]
When two or more kinds of the above-mentioned soluble substances are used in combination, the combination of the two kinds of soluble substances to be mixed is preferably a combination of resin particles and inorganic particles. Both of them have low conductivity, so that the insulation of the interlayer resin insulation layer can be secured, and the thermal expansion can be easily adjusted between the poorly soluble resin and the interlayer resin comprising the roughened surface forming resin composition This is because no crack occurs in the insulating layer, and no peeling occurs between the interlayer resin insulating layer and the conductor circuit.
[0112]
As the liquid phase resin, an uncured solution of the thermosetting resin can be used. As a specific example of such a liquid phase resin, for example, a mixed liquid of an uncured epoxy oligomer and an amine curing agent. Etc.
Examples of the liquid phase rubber include various polybutadiene rubbers such as the above polybutadiene rubber, epoxy modification, urethane modification, (meth) acrylonitrile modification, uncured solutions such as (meth) acrylonitrile / butadiene rubber containing a carboxyl group, etc. Can be used.
[0113]
When preparing the photosensitive resin composition using the liquid phase resin or liquid phase rubber, so that the heat resistant resin matrix and the soluble substance are not compatible with each other uniformly (that is, so as to phase-separate), It is necessary to select these substances.
By mixing the heat-resistant resin matrix selected according to the above criteria and a soluble substance, the liquid-phase resin or liquid-phase rubber “islands” are dispersed in the “sea” of the heat-resistant resin matrix. Alternatively, it is possible to prepare a photosensitive resin composition in which “islands” of a heat-resistant resin matrix are dispersed in a “sea” of a liquid phase resin or a liquid phase rubber.
[0114]
And after hardening the photosensitive resin composition of such a state, a roughened surface can be formed by removing the liquid phase resin or liquid phase rubber of "the sea" or "the island".
[0115]
Examples of the acid used as the roughening solution include phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, and organic acids such as formic acid and acetic acid. Among these, it is desirable to use an organic acid. This is because when the roughening treatment is performed, the metal conductor layer exposed from the via hole is hardly corroded.
As the oxidizing agent, for example, an aqueous solution of chromic acid, chromium sulfuric acid, alkaline permanganate (such as potassium permanganate), or the like is preferably used.
Moreover, as said alkali, aqueous solution, such as sodium hydroxide and potassium hydroxide, is desirable.
[0116]
The average particle size of the soluble substance is desirably 10 μm or less.
Further, a relatively large coarse particle having an average particle diameter of 2 μm or less and a fine particle having a relatively small average particle diameter may be used in combination. That is, a soluble substance having an average particle diameter of 0.1 to 0.5 μm and a soluble substance having an average particle diameter of 1 to 2 μm are combined.
[0117]
Thus, by combining average particles, relatively large coarse particles, and fine particles having a relatively small average particle diameter, the dissolution residue of the electroless plating film is eliminated, and the amount of palladium catalyst under the plating resist is reduced. Furthermore, a shallow and complicated roughened surface can be formed.
Furthermore, by forming a complicated roughened surface, a practical peel strength can be maintained even if the roughened surface has small irregularities.
The coarse particles preferably have an average particle size of more than 0.8 μm and less than 2.0 μm, and the fine particles preferably have an average particle size of 0.1 to 0.8 μm.
[0118]
By combining the coarse particles and fine particles, a shallow and complicated roughened surface can be formed. If the particle size used is coarse particles and the average particle size is less than 2 μm, these particles are dissolved and removed. However, the anchor formed is shallow, and the removed particles are a mixture of coarse particles having a relatively large particle size and fine particles having a relatively small particle size. Is complicated. By forming such a complicated roughened surface, a practical peel strength can be maintained even on a shallow roughened surface.
[0119]
Also, in this case, if the particle size used is coarse particles and the average particle size is less than 2 μm, roughening does not proceed excessively and voids are not generated, and the formed interlayer resin insulation layer is excellent in interlayer insulation. ing.
In the interlayer surface forming resin composition, the particle size of the soluble substance is the length of the longest part of the soluble substance.
[0120]
Further, when the coarse particles have an average particle size of more than 0.8 μm and less than 2.0 μm, and the fine particles have an average particle size of 0.1 to 0.8 μm, the depth of the roughened surface is approximately Rmax = 3 μm. Thus, in the semi-additive method, not only the electroless plating film can be easily removed by etching, but also the Pd catalyst under the electroless plating film can be easily removed, and a practical peel strength of 1.0 to 1.3 kg / cm can be maintained.
[0121]
The shape of the soluble substance is not particularly limited, and examples thereof include a spherical shape and a crushed shape. Moreover, it is desirable that the soluble substance has a uniform shape. This is because a roughened surface having unevenness with uniform roughness can be formed.
[0122]
The roughened surface-forming resin composition may contain an organic solvent so that it can be applied onto a substrate or the like, or is formed into a film so that it can be pressure-bonded onto the substrate or the like. (Hereinafter also referred to as a roughened surface-forming resin film).
When the roughened surface-forming resin composition contains an organic solvent, the content is desirably 10% by weight or less.
[0123]
In the roughened surface-forming resin film, it is desirable that the soluble substance is dispersed substantially uniformly in the heat-resistant resin matrix. A roughened surface with unevenness of uniform roughness can be formed, and even if a via hole or a through hole is formed in a resin film, the adhesion of the metal layer of the conductor circuit formed thereon can be secured. Because it can. Moreover, the said roughened surface formation resin film may be formed so that only a surface layer part which forms a roughened surface may contain a soluble substance. Thereby, since the surface layer portion other than the surface layer portion of the roughened surface-forming resin film is not exposed to the acid or the oxidizing agent, the insulation between the conductor circuits through the interlayer resin insulating layer is reliably maintained.
[0124]
In the roughened surface forming resin film, the blending amount of the soluble substance dispersed in the hardly soluble resin is preferably 3 to 40% by weight with respect to the roughened surface forming resin film. If the blending amount of the soluble substance is less than 3% by weight, a roughened surface having desired irregularities may not be formed. If it exceeds 40% by weight, the soluble substance is dissolved using an acid or an oxidizing agent. When it does, it melt | dissolves to the deep part of a resin film, cannot maintain the insulation between the conductor circuits through the interlayer resin insulation layer which consists of a resin film, and may cause a short circuit.
[0125]
The roughened surface-forming resin film desirably contains a curing agent, other components, etc. in addition to the soluble substance and the heat-resistant resin matrix.
Examples of the curing agent include imidazole curing agents, amine curing agents, guanidine curing agents, epoxy adducts of these curing agents, microcapsules of these curing agents, triphenylphosphine, and tetraphenylphosphorus. And organic phosphine compounds such as nium tetraphenylborate.
[0126]
As for content of the said hardening | curing agent, it is desirable that it is 0.05 to 10 weight% with respect to the resin film for roughening surface formation. If it is less than 0.05% by weight, the roughened surface-forming resin film is insufficiently cured, so that the degree of penetration of the acid or oxidizing agent into the roughened surface-forming resin film increases, and the roughened surface-forming resin The insulation of the film may be impaired. On the other hand, if it exceeds 10% by weight, an excessive curing agent component may denature the composition of the resin, which may lead to a decrease in reliability.
[0127]
Examples of the other components include fillers such as inorganic compounds or resins that do not affect the formation of the roughened surface. Examples of the inorganic compound include silica, alumina, and dolomite. Examples of the resin include polyimide resin, polyacrylic resin, polyamideimide resin, polyphenylene resin, melanin resin, and olefin resin. By containing these fillers, it is possible to improve the performance of the printed wiring board by matching the thermal expansion coefficient, improving heat resistance, and chemical resistance.
[0128]
Moreover, the said resin film for roughening surface formation may contain the solvent. Examples of the solvent include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and aromatic hydrocarbons such as ethyl acetate, butyl acetate, cellosolve acetate, toluene, and xylene. These may be used alone or in combination of two or more.
[0129]
(7) Next, when forming an interlayer resin insulation layer using a thermosetting resin or a resin composite as the material, the uncured resin insulation layer is subjected to curing treatment and a via hole opening is formed. And an interlayer resin insulation layer. In this step, a through hole may be formed as necessary.
The via hole opening is preferably formed by laser processing. The laser treatment may be performed before the curing treatment or after the curing treatment.
When an interlayer resin insulating layer made of a photosensitive resin is formed, a via hole opening may be provided by performing exposure and development processes. In this case, the exposure and development processes are performed before the curing process.
[0130]
When an interlayer resin insulation layer using a thermoplastic resin as the material is formed, a via hole opening can be formed in the resin layer made of the thermoplastic resin by laser processing to form an interlayer resin insulation layer. .
[0131]
At this time, examples of the laser to be used include a carbon dioxide laser, an excimer laser, a UV laser, and a YAG laser.
These lasers may be selectively used in consideration of the via hole opening to be formed, the shape of the through hole, and the like.
[0132]
In the case of forming the via hole openings, a large number of via hole openings can be formed at a time by irradiating laser light with a hologram type excimer laser through a mask.
In addition, when a via hole opening is formed using a short pulse carbon dioxide laser, there is little resin residue in the opening, and damage to the resin at the periphery of the opening is small.
[0133]
In addition, by irradiating laser light through an optical system lens and a mask, a large number of openings for via holes can be formed at one time.
This is because laser light having the same intensity and the same irradiation angle can be simultaneously irradiated to a plurality of portions through the optical system lens and the mask.
[0134]
The through hole formed in the mask is preferably a perfect circle in order to make the spot shape of the laser beam a perfect circle, and the diameter of the through hole is preferably about 0.1 to 2 mm.
When the carbon dioxide laser is used, the pulse interval is 10^-Four-10^-8It is desirable to be seconds. Moreover, it is desirable that the time for irradiating the laser for forming the opening is 10 to 500 μsec.
[0135]
When the via hole opening is formed by laser light, especially when a carbon dioxide laser is used, it is desirable to perform desmear treatment. The desmear treatment can be carried out using an oxidizing agent comprising an aqueous solution such as chromic acid or permanganate. Oxygen plasma, CF_Four And may be treated with a mixed plasma of oxygen and oxygen, corona discharge, or the like. Further, the surface can be modified by irradiating with ultraviolet rays using a low-pressure mercury lamp.
[0136]
Although the thickness of the said interlayer resin insulation layer is not specifically limited, 5-50 micrometers is desirable.
If the thickness is less than 5 μm, insulation between adjacent conductor circuits may not be maintained. On the other hand, if the thickness exceeds 50 μm, the resin remains on the bottom when via holes are formed. Or the shape of the via hole opening or the like may be tapered toward the bottom.
Moreover, the opening diameter of the opening for the via hole is not particularly limited, but is usually preferably 40 to 200 μm.
[0137]
Moreover, when forming a through-hole in the board | substrate with which the interlayer resin insulation layer was formed, a through-hole is formed using a 50-300 micrometers diameter drill, a laser beam, etc.
In the case where the through hole is formed, a through layer can be formed by forming a conductor layer on the inner wall surface of the through hole in a step to be described later. By forming the through hole, the substrate and the interlayer resin can be formed. Conductor circuits can be electrically connected via the insulating layer.
[0138]
(8) Next, if necessary, an acid or an oxidant is used for the surface of the interlayer resin insulating layer including the inner wall of the opening for the via hole and the inner wall of the through hole when the through hole is formed in the above process. To form a roughened surface.
Examples of the acid include sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, and examples of the oxidizing agent include permanganates such as chromic acid, chromium sulfuric acid, and sodium permanganate.
In addition, the roughened surface may be formed using plasma treatment or the like.
[0139]
Specifically, when the interlayer resin insulation layer is formed using a roughened surface forming resin composition or the like, it is desirable to form a roughened surface using an acid or an oxidizing agent, In the case of using it, it is desirable to form a roughened surface using plasma treatment or the like.
[0140]
This roughened surface is formed in order to improve the adhesion between the interlayer resin insulation layer and the electroless plating film formed thereon, and is sufficient between the interlayer resin insulation layer and the electroless plating film. If it has good adhesion, it does not have to be formed.
[0141]
After that, when the roughened surface is formed using acid, an aqueous solution such as an alkali is used, and when the roughened surface is formed using an oxidizing agent, the inside of the via hole or the through hole is formed using a neutralizing solution. Neutralize. By this operation, acid and oxidant are removed so as not to affect the next process.
[0142]
(9) Next, if necessary, a catalyst is applied to the formed roughened surface. Examples of the catalyst include palladium as described above.
At this time, in order to reliably apply the catalyst, dry treatment such as plasma treatment of oxygen, nitrogen, etc. and corona treatment removes the residue of acid or oxidant and reforms the surface of the interlayer resin insulation layer By doing so, it is possible to reliably provide a catalyst and improve the metal deposition during electroless plating and the adhesion of the electroless plating layer to the interlayer resin insulation layer. In this case, a great effect can be obtained.
[0143]
(9) Next, an electroless plating film is formed on the surface of the interlayer resin insulation layer including the inner wall surface of the via hole opening by using the method including the steps (A) to (C) described above.
Although the thickness of the electroless plating film formed here is not specifically limited, Usually, about 6-12 micrometers is desirable.
[0144]
In addition, when the through hole is formed in the step (7), an electroless plating film is formed on the wall surface of the through hole by using the above method when forming a conductor circuit on the interlayer resin insulation layer. It is good also as a through hole by doing.
[0145]
When the through hole is formed, it is desirable to perform the following processing steps. That is, the surface of the electroless plating layer and the inner wall of the through hole are blackened (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of organic acid and cupric complex, treatment with Cu-Ni-P acicular alloy plating, etc. The roughening process is performed. Thereafter, the resin filler or the like is further filled, and then the surface layer portion of the resin filler and the electroless plating film surface are planarized by using a polishing method such as buffing.
Furthermore, electroless plating is performed, and an electroless plating layer is formed on the electroless plating film already formed and the surface layer portion of the resin filler, thereby forming a lid plating layer on the through hole.
[0146]
(11) Next, a plating resist is formed on the interlayer resin insulation layer-formed wiring board on which the electroless plating film is formed using the method described above. Next, as described above, the electroless plating film is formed on the plating resist non-forming portion using the electroless plating film as a plating lead.
(12) Further, after removing the plating resist with a strong alkaline aqueous solution, etching is performed to remove the electroless plating layer, thereby forming an independent pattern conductor circuit.
As an etchant used here, an aqueous solution of persulfate such as sulfuric acid / hydrogen peroxide solution, ferric chloride, cupric chloride, ammonium persulfate, hydrochloric acid, nitric acid, hot dilute sulfuric acid and the like can be used. Moreover, while removing an electroless plating film using the etching liquid containing a cupric complex and an organic acid, an interlayer surface may be formed on the surface of the conductor circuit.
[0147]
(13) Next, if necessary, the conductor circuit is roughened by the same method as described in (5), and then the steps (6) to (12) are repeated, so that the conductor circuit and the interlayer are repeated. A substrate in which resin insulation is sequentially laminated can be manufactured.
[0148]
(14) Next, a solder resist layer is formed on the substrate surface including the uppermost conductor circuit, and further, the solder resist layer is opened to form a solder pad, and then the solder pad is filled with a solder paste, A solder bump is formed by reflow. After that, by arranging pins or forming solder balls on the connection surface of the external substrate, a PGA (Pin Grid Array) or BGA (Ball Grid Array) is obtained.
[0149]
The solder resist layer can be formed using, for example, a solder resist composition comprising a polyphenylene ether resin, a polyolefin resin, a fluororesin, a thermoplastic elastomer, an epoxy resin, a polyimide resin, and the like. For example, the same resin as the resin used for the interlayer resin insulating layer can be used.
[0150]
Examples of solder resist compositions other than those described above include, for example, (meth) acrylates of novolak epoxy resins, imidazole curing agents, bifunctional (meth) acrylic acid ester monomers, and (meth) acrylic acid having a molecular weight of about 500 to 5,000. Examples include paste polymers containing ester polymers, thermosetting resins composed of bisphenol-type epoxy resins, photosensitive monomers such as polyvalent acrylic monomers, glycol ether solvents, and the viscosity at 25 ° C. It is desirable that the pressure is adjusted to 1 to 10 Pa · s.
Examples of the (meth) acrylate of the novolak type epoxy resin include an epoxy resin obtained by reacting a glycidyl ether of phenol novolak or cresol novolak with acrylic acid or methacrylic acid.
[0151]
The bifunctional (meth) acrylic acid ester monomer is not particularly limited, and examples thereof include acrylic acid and methacrylic acid esters of various diols, and commercially available products thereof include R- manufactured by Nippon Kayaku Co., Ltd. 604, PM2, PM21 and the like.
[0152]
The solder resist composition may contain an elastomer or a permanent filler.
When the elastomer resist is blended, the formed solder resist layer absorbs or relaxes the stress even if the solder resist layer is subjected to stress due to the flexibility and rebound resilience of the elastomer. As a result, it is possible to suppress the occurrence of cracks and peeling in the solder resist layer after mounting electronic components such as IC chips on the manufacturing process of the multilayer printed wiring board and the manufactured multilayer printed wiring board. Even when this occurs, the crack cannot grow greatly.
[0153]
Examples of the method of opening the solder resist layer include a method of irradiating a laser beam as in the method of forming a via hole opening.
[0154]
In addition, when a photosensitive solder resist composition is used as the solder resist composition, after forming the solder resist layer, the photoresist is placed on the solder resist layer and subjected to exposure and development treatment. The solder resist layer can be opened.
[0155]
The conductor circuit portion exposed by opening the solder resist layer is usually preferably coated with a corrosion-resistant metal such as nickel, palladium, gold, silver, or platinum. Specifically, it is desirable to form the coating layer with a metal such as nickel-gold, nickel-silver, nickel-palladium, nickel-palladium-gold.
The coating layer can be formed by, for example, plating, vapor deposition, electrodeposition, or the like, and among these, plating is desirable from the viewpoint of excellent uniformity of the coating layer.
[0156]
In addition, plasma treatment with oxygen, carbon tetrachloride, or the like may be performed in a timely manner for a character printing process for forming product recognition characters or the like or for modifying the solder resist layer.
The above method is based on the semi-additive method, but the full additive method may be adopted.
[0157]
Next, the manufacturing method of the multilayer printed wiring board of 2nd this invention is demonstrated.
According to a second aspect of the present invention, there is provided a multilayer printed wiring board manufacturing method comprising: a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate; and the conductor circuits are connected via via holes. A manufacturing method comprising at least the following steps (a) to (f):
(A) providing a catalyst on the surface of the substrate or the interlayer resin insulation layer;
(B) a step of performing pretreatment on the substrate or the interlayer resin insulation layer provided with the catalyst, using the pretreatment liquid for electroless plating according to the present invention;
(C) forming an electroless plating film on the resin substrate or the interlayer resin insulation layer;
(D) forming an electrolytic plating film on the electroless plating film;
(E) forming an etching resist on a portion of the electrolytic plating film; and
(F) A step of removing the electrolytic plating film and the electroless plating film under the etching resist non-forming portion by an etching process.
[0158]
According to the second method for producing a multilayer printed wiring board of the present invention, the surface of the substrate or the interlayer resin insulation layer is subjected to pretreatment using the pretreatment liquid for electroless plating of the present invention, and then electroless plating is performed. Since the conductor circuit is formed by processing, electrolytic plating, etc., the adhesion between the substrate and the interlayer resin insulation layer and the conductor circuit is excellent, producing a multilayer printed wiring board with excellent reliability and electrical characteristics can do.
[0159]
The method for producing a multilayer printed wiring board according to the second aspect of the present invention is compared with the method for producing a multilayer printed wiring board according to the first aspect of the present invention, the steps (a) to (f), that is, a substrate or an interlayer resin insulation layer. Since only the process of forming the conductor circuit is different, only the processes (a) to (f) will be described, and the description of all the manufacturing processes for manufacturing the multilayer printed wiring board will be omitted.
[0160]
In the method for producing a multilayer printed wiring board according to the second aspect of the present invention, a catalyst is applied to the surface of the substrate or the interlayer resin insulation layer.
As said catalyst, palladium metal etc. are mentioned, for example.
Also in the method for producing a multilayer printed wiring board according to the second aspect of the present invention, it is desirable to form a roughened surface in advance on the surface of the substrate or the interlayer resin insulation layer before applying the catalyst.
When palladium metal is used as the catalyst, a method similar to the method for producing a multilayer printed wiring board according to the first aspect of the present invention can be used as a method for applying the catalyst.
[0161]
Next, the substrate to which the catalyst is applied or the interlayer resin insulating layer is pretreated using the pretreatment liquid for electroless plating of the present invention.
The pretreatment is performed by immersing the substrate or the interlayer resin insulation layer-formed wiring board in the pretreatment liquid for electroless plating.
[0162]
At this time, the temperature of the pretreatment liquid for electroless plating is preferably 20 to 50 ° C. as in the method for producing a multilayer printed wiring board according to the first aspect of the present invention.
The immersion time in the pretreatment liquid for electroless plating is also preferably 0.5 to 5 minutes, as in the method for producing a multilayer printed wiring board according to the first aspect of the present invention.
[0163]
Next, an electroless plating film is formed on the pretreated substrate or interlayer resin layer.
The electroless plating film can be formed by immersing a substrate or an interlayer resin insulation layer-formed wiring board in an electroless plating solution. Here, as the electroless plating solution, the same electroless plating solution as in the method for producing a multilayer printed wiring board according to the first invention can be used.
[0164]
Next, an electrolytic plating film is formed on the electroless plating film.
The electrolytic plating film can be formed by using the already formed electroless plating film as a plating lead.
Specifically, for example, an electrolytic copper plating film can be formed by using an electrolytic plating solution containing sulfuric acid, copper sulfate and an additive.
[0165]
Next, an etching resist is formed on a part of the electrolytic plating film, that is, a part corresponding to a conductor circuit forming part.
The etching resist can be formed, for example, by applying a photosensitive dry film or applying a liquid resist and then performing an exposure development process.
[0166]
Next, by performing an etching process, the electrolytic plating film and the electroless plating film in the conductor circuit non-forming portion are removed, and then the etching resist is stripped with a strong alkaline aqueous solution.
Examples of the etching treatment include sulfuric acid / hydrogen peroxide aqueous solution, chemical etching using an aqueous solution of persulfate such as ferric chloride, cupric chloride and ammonium persulfate as an etching solution, physical etching by ion beam etching, etc. Is used.
[0167]
Through these steps, a conductor circuit can be formed on the substrate or the interlayer resin insulation layer.
In addition, in the method for producing a multilayer printed wiring board according to the second aspect of the present invention, before the electroless plating film is formed, the surface of the substrate or the interlayer resin insulation layer is formed using the pretreatment liquid for electroless plating according to the present invention. Since the pretreatment has been performed, a conductor circuit having excellent adhesion to the substrate and the interlayer resin insulation layer can be formed.
[0168]
Next, the manufacturing method of the multilayer printed wiring board of 3rd this invention is demonstrated.
According to a third aspect of the present invention, there is provided a multilayer printed wiring board manufacturing method comprising: a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate; and the conductor circuits are connected through via holes. It is a manufacturing method, Comprising: At least the process of following (A)-(E) is included, It is characterized by the above-mentioned.
(A) A step of applying a catalyst to the surface of the substrate or the interlayer resin insulation layer,
(B) The substrate or the interlayer resin insulation layer provided with the catalyst is pretreated using the treatment solution for electroless plating of the present invention, and then the substrate or the interlayer resin insulation layer is coated on the substrate or the interlayer resin insulation layer. Forming an electrolytic plating film;
(C) forming a plating resist on a part of the electroless plating film;
(D) forming an electrolytic plating film on the plating resist non-forming portion; and
(E) A step of removing the electroless plating film under the plating resist after removing the plating resist.
[0169]
According to the third method for producing a multilayer printed wiring board of the present invention, the electroless plating treatment liquid of the present invention is used to pre-treat the surface of the substrate or the interlayer resin insulation layer, and then perform the electroless plating process. In addition, the conductive circuit is formed by performing electroplating, etc., so the adhesion between the substrate and the interlayer resin insulation layer and the conductive circuit is excellent, and the multilayer printed wiring with excellent reliability and electrical characteristics A board can be manufactured.
[0170]
The method for producing a multilayer printed wiring board according to the third aspect of the present invention uses a treatment liquid for electroless plating according to the present invention as compared with the method for producing a multilayer printed wiring board according to the first aspect of the present invention. The only difference is that after the surface of the layer is pretreated, an electroless plating treatment is performed.
That is, in the method for producing a multilayer printed wiring board according to the first aspect of the present invention, the electroless plating solution used for forming the electroless plating film is not particularly limited, whereas the multilayer printed wiring according to the third aspect of the present invention. The method for producing a plate is characterized in that an electroless plating film is formed using an “electroless plating solution comprising an aqueous solution containing an alkaline compound, a reducing agent, copper ions, and tartaric acid or a salt thereof”.
[0171]
Therefore, only the method for forming the electroless plating film will be described here.
The electroless plating film is formed by immersing the substrate or interlayer resin insulation layer-formed wiring board that has been pretreated on the surface thereof in the electroless plating solution that constitutes the electroless plating treatment solution of the present invention. To do.
The conditions for immersing the substrate or the interlayer resin insulation layer-formed wiring board in the electroless plating solution are not particularly limited, and may be appropriately selected in consideration of the composition of the electroless plating solution and the material of the object to be plated. Good. Specifically, for example, an electroless plating film can be formed by immersing in an electroless plating solution at 25 to 35 ° C. for 10 to 20 minutes.
[0172]
Next, the manufacturing method of the multilayer printed wiring board of the 4th aspect of this invention is demonstrated.
According to a fourth aspect of the present invention, there is provided a multilayer printed wiring board manufacturing method comprising: a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate; and the conductor circuits are connected through via holes. A manufacturing method comprising at least the following steps (a) to (e):
(A) providing a catalyst on the surface of the substrate or the interlayer resin insulation layer;
(B) The substrate or the interlayer resin insulation layer provided with the catalyst is pretreated using the treatment liquid for electroless plating of the present invention, and then applied to the substrate or the interlayer resin insulation layer. Forming an electrolytic plating film;
(C) forming an electrolytic plating film on the electroless plating film;
(D) forming an etching resist on a portion of the electrolytic plating film; and
(E) A step of removing the electrolytic plating film and the electroless plating film under the etching resist non-forming portion by an etching process.
[0173]
According to the fourth method for producing a multilayer printed wiring board of the present invention, after the pretreatment is performed on the surface of the substrate or the interlayer resin insulation layer using the electroless plating treatment liquid of the present invention, the electroless plating treatment is performed. In addition, the conductive circuit is formed by performing electroplating, etc., so the adhesion between the substrate and the interlayer resin insulation layer and the conductive circuit is excellent, and the multilayer printed wiring with excellent reliability and electrical characteristics A board can be manufactured.
[0174]
The method for producing a multilayer printed wiring board according to the fourth aspect of the present invention uses a treatment liquid for electroless plating according to the present invention as compared with the method for producing a multilayer printed wiring board according to the second aspect of the present invention. The only difference is that after the surface of the layer is pretreated, an electroless plating treatment is performed.
That is, in the method for producing a multilayer printed wiring board according to the second invention, the electroless plating solution used for forming the electroless plating film is not particularly limited, whereas the multilayer printed wiring according to the fourth invention. The method for producing a plate is characterized in that an electroless plating film is formed using an “electroless plating solution comprising an aqueous solution containing an alkaline compound, a reducing agent, copper ions, and tartaric acid or a salt thereof”.
[0175]
Therefore, only the method for forming the electroless plating film will be described here.
The electroless plating film is formed by immersing the substrate or interlayer resin insulation layer-formed wiring board that has been pretreated on the surface thereof in the electroless plating solution that constitutes the electroless plating treatment solution of the present invention. To do.
The conditions for immersing the substrate or the interlayer resin insulation layer-formed wiring board in the electroless plating solution are not particularly limited, and may be appropriately selected in consideration of the composition of the electroless plating solution and the material of the object to be plated. Good. Specifically, for example, an electroless plating film can be formed by immersing in an electroless plating solution at 25 to 35 ° C. for 10 to 20 minutes.
[0176]
【Example】
Hereinafter, the present invention will be described in more detail.
Example 1
A. Production of resin film for interlayer resin insulation layer
30 parts by weight of bisphenol A type epoxy resin (epoxy equivalent 469, Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.), 40 parts by weight of cresol novolac type epoxy resin (epoxy equivalent 215, Epiklon N-673 manufactured by Dainippon Ink & Chemicals, Inc.), triazine 30 parts by weight of a structure-containing phenol novolak resin (phenolic hydroxyl group equivalent 120, Phenolite KA-7052 manufactured by Dainippon Ink & Chemicals, Inc.) was dissolved in 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha with stirring. Thereto, terminal epoxidized polybutadiene rubber (Nagase Kasei Kogyo Denarex R-45EPT) 15 parts by weight, 2-phenyl-4,5-bis (hydroxymethyl) imidazole pulverized product 1.5 parts by weight, finely pulverized silica 2 parts by weight , Silicon Added to prepare an epoxy resin composition agent 0.5 parts by weight.
The obtained epoxy resin composition was applied on a PET film having a thickness of 38 μm using a roll coater so that the thickness after drying was 50 μm, and then dried at 80 to 120 ° C. for 10 minutes, whereby an interlayer resin was obtained. A resin film for an insulating layer was produced.
[0177]
B. Preparation of resin filler
100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., Ltd., molecular weight: 310, YL983U), SiO having an average particle diameter of 1.6 μm and a maximum particle diameter of 15 μm or less coated with a silane coupling agent on the surface₂ 170 parts by weight of spherical particles (manufactured by Adtech, CRS 1101-CE) and 1.5 parts by weight of a leveling agent (Perenol S4, manufactured by San Nopco) are placed in a container and mixed by stirring. A 49 Pa · s resin filler was prepared. As the curing agent, 6.5 parts by weight of an imidazole curing agent (manufactured by Shikoku Kasei Co., Ltd., 2E4MZ-CN) was used.
[0178]
C. Manufacture of multilayer printed wiring boards
(1) A copper-clad laminate in which 18 μm copper foil 8 is laminated on both surfaces of an insulating substrate 1 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 0.8 mm was used as a starting material (see FIG. 1 (a)). First, the copper-clad laminate was drilled, subjected to electroless plating, and etched into a pattern to form the lower conductor circuit 4 and the through holes 9 on both sides of the substrate.
[0179]
(2) The substrate on which the through hole 9 and the lower conductor circuit 4 are formed is washed with water and dried, followed by NaOH (10 g / l), NaClO₂ (40 g / l), Na_Three PO_Four Blackening treatment using an aqueous solution containing (6 g / l) as a blackening bath (oxidation bath), and NaOH (10 g / l), NaBH_Four Reduction treatment using an aqueous solution containing (6 g / l) as a reducing bath was performed, and roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 1B).
[0180]
(3) After preparing the resin filler described in the above B, within 24 hours after preparation by the following method, the inside of the through hole 9 and the outer periphery of the conductor circuit 4 and the conductor circuit non-formed portion on one side of the substrate 1 A layer of the resin filler 10 was formed on the part.
That is, first, a resin filler was pushed into a through hole using a squeegee, and then dried under conditions of 100 ° C. and 20 minutes. Next, a mask having an opening corresponding to the conductor circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed on the conductor circuit non-forming portion which is a concave portion using a squeegee. The film was dried at 20 ° C. for 20 minutes (see FIG. 1 (c)).
[0181]
(4) One side of the substrate after the processing of (3) above is applied to the surface of the inner layer copper pattern 4 or the land surface of the through hole 9 by belt sander polishing using # 600 belt polishing paper (manufactured by Sankyo Rikagaku). Polishing was performed so that the resin filler 10 did not remain, and then buffing was performed to remove scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate.
Next, the resin filler 10 was cured by heat treatment at 100 ° C. for 1 hour and 150 ° C. for 1 hour.
[0182]
In this way, the surface layer portion of the resin filler 10 and the surface of the lower conductor circuit 4 formed in the through hole 9 and the conductor circuit non-forming portion are flattened, and the resin filler 10 and the side surface 4a of the lower conductor circuit 4 are formed. A substrate was obtained in which the inner wall surface 9a of the through hole 9 and the resin filler 10 were in close contact with each other through the roughened surface (see FIG. 1D). That is, by this step, the surface of the resin filler 10 and the surface of the lower conductor circuit 4 are flush.
[0183]
(5) After washing the substrate with water and acid degreasing, soft etching is performed, and then an etching solution is sprayed on both sides of the substrate to spray the surface of the lower conductor circuit 4, the land surface of the through hole 9, and the inner wall. Thus, roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 2A).
As an etchant, an etchant (MEC Etch Bond, manufactured by MEC Co.) consisting of 10 parts by weight of imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride was used.
[0184]
(6) A resin film for an interlayer resin insulation layer that is slightly larger than the substrate prepared in A is placed on both sides of the substrate, and the pressure is 4 kgf / cm.² After being temporarily crimped and cut under the conditions of a temperature of 80 ° C. and a crimping time of 10 seconds, an interlayer resin insulation layer was formed by pasting using a vacuum laminator apparatus by the following method (see FIG. 3B). ). That is, a resin film for an interlayer resin insulation layer is placed on a substrate with a vacuum degree of 0.5 Torr and a pressure of 4 kgf / cm.² The film was subjected to main pressure bonding under conditions of a temperature of 80 ° C. and a pressure bonding time of 60 seconds, and then thermally cured at 170 ° C. for 30 minutes.
[0185]
(7) Next, CO 2 having a wavelength of 10.4 μm is passed through a mask in which a through hole having a thickness of 1.2 mm is formed on the interlayer resin insulation layer 2.₂ With a gas laser, a via hole opening with a diameter of 80 μm in the interlayer resin insulation layer 2 under the conditions of a beam diameter of 4.0 mm, a top hat mode, a pulse width of 8.0 μsec, a mask through hole diameter of 1.0 mm, and one shot. 6 was formed (see FIG. 2C).
[0186]
(8) The substrate on which the via-hole opening 6 has been formed is immersed in an 80 ° C. solution containing 60 g / l permanganic acid for 10 minutes to dissolve and remove the epoxy resin particles present on the surface of the interlayer resin insulation layer 2. Thus, the surface of the interlayer resin insulating layer 2 including the inner wall of the via hole opening 6 was roughened (see FIG. 2D).
[0187]
(9) Next, the substrate after the above treatment was immersed in a neutralization solution (manufactured by Shipley Co., Ltd.) and washed with water.
Further, by applying a palladium catalyst to the surface of the roughened substrate (roughening depth 3 μm), catalyst nuclei are attached to the surface of the interlayer resin insulation layer 2 and the inner wall surface of the via hole opening 6. (Not shown). That is, the substrate is made of palladium chloride (PbCl₂ ) And stannous chloride (SnCl)₂ The catalyst was imparted by immersing it in a catalyst solution containing) and depositing palladium metal.
[0188]
(10) Next, pretreatment was performed by immersing the substrate in a pretreatment solution for electroless plating having the following composition.
[Pretreatment solution for electroless plating]
NaOH 0.10 mol / l
HCHO 0.10 mol / l
[Pretreatment conditions]
Immersion temperature 30 ° C
Liquid temperature 3 minutes
[0189]
(11) Next, the pretreated substrate is immersed in an electroless copper plating aqueous solution having the following composition, and an electroless copper plating film 12 having a thickness of 0.6 to 3.0 μm is formed on the entire rough surface. As a result, a substrate was obtained in which the electroless copper plating film 12 was formed on the surface of the interlayer resin insulation layer including the inner wall of the via hole opening (see FIG. 3A).
[Electroless plating aqueous solution]
NiSO_Four                   0.003 mol / l
Tartaric acid 0.200 mol / l
Copper sulfate 0.030 mol / l
HCHO 0.050 mol / l
NaOH 0.100 mol / l
α, α'-bipyridyl 100 mg / l
Polyethylene glycol (PEG) 0.10 g / l
[Electroless plating conditions]
40 minutes at 34 ° C liquid temperature
[0190]
(12) A commercially available photosensitive dry film is attached to the substrate on which the electroless copper plating film 12 is formed, and a mask is placed on the substrate, and 100 mJ / cm.² The plating resist 3 having a thickness of 20 μm was provided by developing with a 0.8% sodium carbonate aqueous solution (see FIG. 3B).
[0191]
(13) Next, the substrate is washed with 50 ° C. water, degreased, washed with 25 ° C. water, and further washed with sulfuric acid. Then, an electrolytic copper plating film 13 having a thickness of 20 μm was formed (see FIG. 3C).
[Electrolytic plating solution]
Sulfuric acid 2.24 mol / l
Copper sulfate 0.26 mol / l
Additive 19.5 ml / l
(Manufactured by Atotech Japan, Kaparaside GL)
[Electrolytic plating conditions]
Current density 1 A / dm²
65 minutes
Temperature 22 ± 2 ° C
[0192]
(14) Further, after removing the plating resist 3 with 5% KOH, the electroless plating film under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide. A conductor circuit 5 (including a via hole 7) was formed (see FIG. 3D).
[0193]
(15) Next, the same process as in (5) above was performed to form a roughened surface on the conductor circuit surface (see FIG. 4A).
(16) By repeating the steps (6) to (15) above, a further upper conductor circuit was formed to obtain a multilayer wiring board (see FIGS. 4B to 5B).
[0194]
(17) Next, the photosensitizing property obtained by acrylated 50% of an epoxy group of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) to a concentration of 60% by weight. 46.67 parts by weight of oligomer (molecular weight: 4000), 80% by weight of bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Co., Ltd.) dissolved in methyl ethyl ketone, 15.0 parts by weight, imidazole curing agent (Shikoku Kasei Co., Ltd., trade name: 2E4MZ-CN) 1.6 parts by weight, photofunctional monomer bifunctional acrylic monomer (Nippon Kayaku Co., Ltd., trade name: R604) 4.5 parts by weight, also polyvalent acrylic monomer ( Kyoei Chemical Co., Ltd., trade name: DPE6A) 1.5 parts by weight, dispersion antifoaming agent (San Nopco, S-65) Take 1 part by weight in a container, stir and mix to prepare a mixed composition. 2.0 parts by weight of benzophenone (manufactured by Kanto Chemical Co., Inc.) as a photopolymerization initiator for this mixed composition, as a photosensitizer By adding 0.2 part by weight of Michler's ketone (manufactured by Kanto Chemical Co., Inc.), a solder resist composition having a viscosity adjusted to 2.0 Pa · s at 25 ° C. was obtained.
Viscosity measurement was performed using a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.). In the case of 4 or 6 rpm, the rotor No. 3 according.
[0195]
(18) Next, the solder resist composition is applied to both surfaces of the multilayer wiring board at a thickness of 20 μm, and after drying at 70 ° C. for 20 minutes and 70 ° C. for 30 minutes, the solder resist is applied. A photomask with a thickness of 5 mm on which the pattern of the opening is drawn is brought into close contact with the solder resist layer and 1000 mJ / cm² Were exposed to UV light and developed with DMTG solution to form an opening having a diameter of 200 μm.
Further, the solder resist layer is cured by heating at 80 ° C. for 1 hour, 100 ° C. for 1 hour, 120 ° C. for 1 hour, and 150 ° C. for 3 hours. A solder resist pattern layer 14 having a thickness of 20 μm was formed. A commercially available solder resist composition can also be used as the solder resist composition.
[0196]
(19) Next, the substrate on which the solder resist layer 14 is formed is made of nickel chloride (2.3 × 10^-1mol / l), sodium hypophosphite (2.8 × 10^-1mol / l), sodium citrate (1.6 × 10^-1The nickel plating layer 15 having a thickness of 5 μm was formed in the opening by immersing in an electroless nickel plating solution having a pH of 4.5 containing 1 mol / l). Further, the substrate was made of potassium gold cyanide (7.6 × 10 6^-3mol / l), ammonium chloride (1.9 × 10^-1mol / l), sodium citrate (1.2 × 10^-1mol / l), sodium hypophosphite (1.7 × 10^-1The gold plating layer 16 having a thickness of 0.03 μm was formed on the nickel plating layer 15 by immersing in an electroless gold plating solution containing 1 mol / l) at 80 ° C. for 7.5 minutes.
[0197]
(20) Thereafter, a solder paste containing tin-lead is printed on the opening of the solder resist layer 14 on the surface on which the IC chip of the substrate is placed, and further, the tin- After printing the solder paste containing antimony, solder bumps (solder bodies) 17 were formed by reflowing at 200 ° C., and a multilayer printed wiring board having the solder bumps 17 was manufactured (see FIG. 5C).
[0198]
(Example 2)
A multilayer printed wiring board was produced in the same manner as in Example 1 except that the NaOH concentration in the pretreatment solution for electroless plating was 0.025 mol / l.
[0199]
(Example 3)
A multilayer printed wiring board was produced in the same manner as in Example 1 except that the concentration of HCHO in the pretreatment liquid for electroless plating was changed to 0.10 mol / l.
[0200]
Example 4
In electroless plating solution, NiSO_Four Instead of CoSO_Four (Concentration: A multilayer printed wiring board was produced in the same manner as in Example 1 except that 0.002 mol / l was used.
[0201]
(Example 5)
A. Preparation of a resin composition for forming the roughened surface of the upper layer
(1) 400 parts by weight of a resin solution prepared by dissolving 25% acrylate of cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) in diethylene glycol dimethyl ether (DMDG) at a concentration of 80% by weight, a photosensitive monomer ( Toa Gosei Co., Ltd., Aronix M325) 60 parts by weight, antifoaming agent (Sannopco S-65) 5 parts by weight and N-methylpyrrolidone (NMP) 35 parts by weight are placed in a container and mixed by stirring. Prepared.
[0202]
(2) 80 parts by weight of polyethersulfone (PES), 72 parts by weight of epoxy resin particles (manufactured by Sanyo Kasei Co., Ltd., polymer pole) having an average particle diameter of 1.0 μm and 31 parts by weight having an average particle diameter of 0.5 μm After taking in another container and stirring and mixing, 257 parts by weight of NMP was further added, and stirring and mixing was performed with a bead mill to prepare another mixed composition.
[0203]
(3) 20 parts by weight of an imidazole curing agent (manufactured by Shikoku Kasei Co., Ltd., 2E4MZ-CN), 20 parts by weight of a photopolymerization initiator (benzophenone), 4 parts by weight of a photosensitizer (manufactured by Ciba Specialty Chemicals, EAB) and A mixed composition was prepared by taking 16 parts by weight of NMP in another container and stirring and mixing.
And the resin composition for roughening surface formation was obtained by mixing the mixed composition prepared by (1), (2) and (3).
[0204]
B. Preparation of resin composition for forming roughened surface of lower layer
(1) 400 parts by weight of a resin solution prepared by dissolving 25% acrylate of cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) in diethylene glycol dimethyl ether (DMDG) at a concentration of 80% by weight, a photosensitive monomer ( Toa Gosei Co., Ltd., Aronix M325) 60 parts by weight, antifoaming agent (Sannopco S-65) 5 parts by weight and N-methylpyrrolidone (NMP) 35 parts by weight are placed in a container and mixed by stirring. Prepared.
[0205]
(2) After 80 parts by weight of polyethersulfone (PES) and 145 parts by weight of epoxy resin particles (manufactured by Sanyo Kasei Co., Ltd., polymer pole) having an average particle size of 0.5 μm are put in another container and stirred and mixed, Further, 285 parts by weight of NMP was added and stirred and mixed by a bead mill to prepare another mixed composition.
[0206]
(3) 20 parts by weight of an imidazole curing agent (manufactured by Shikoku Kasei Co., Ltd., 2E4MZ-CN), 20 parts by weight of a photopolymerization initiator (benzophenone), 4 parts by weight of a photosensitizer (manufactured by Ciba Specialty Chemicals, EAB) and A mixed composition was prepared by taking 16 parts by weight of NMP in another container and stirring and mixing.
And the adhesive agent for electroless plating was obtained by mixing the mixed composition prepared by (1), (2) and (3).
[0207]
C. Preparation of resin filler
In the same manner as in Example 1, a resin filler was prepared.
[0208]
D. Method for manufacturing printed wiring board
(1) A copper-clad laminate in which 18 μm copper foil 8 is laminated on both surfaces of a substrate 1 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 0.8 mm was used as a starting material (FIG. 6 ( a)). First, the copper-clad laminate was drilled, subjected to electroless plating, and etched into a pattern to form the lower conductor circuits 4 and the through holes 9 on both surfaces of the substrate 1.
[0209]
(2) The substrate on which the through hole 9 and the lower conductor circuit 4 are formed is washed with water and dried, followed by NaOH (10 g / l), NaClO₂ (40 g / l), Na_Three PO_Four Blackening treatment using an aqueous solution containing (16 g / l) as a blackening bath (oxidation bath), and NaOH (19 g / l), NaBH_Four Reduction treatment using an aqueous solution containing (5 g / l) as a reduction bath was performed, and roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 6B).
[0210]
(3) After preparing the resin filler described in C above, within 24 hours after preparation by the following method, the inside of the through hole 9 and the outer periphery of the conductor circuit 4 and the conductor circuit non-formed portion on one side of the substrate 1 A layer of the resin filler 10 was formed on the part.
That is, first, a resin filler was pushed into a through hole using a squeegee, and then dried under conditions of 100 ° C. and 20 minutes. Next, a mask having an opening corresponding to the conductor circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed on the conductor circuit non-forming portion which is a concave portion using a squeegee. Drying was performed at 20 ° C. for 20 minutes (see FIG. 6C).
[0211]
(4) One side of the substrate after the processing of (3) above is applied to the surface of the inner layer copper pattern 4 or the land surface of the through hole 9 by belt sander polishing using # 600 belt polishing paper (manufactured by Sankyo Rikagaku). Polishing was performed so that the resin filler 10 did not remain, and then buffing was performed to remove scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate.
Next, the resin filler 10 was cured by heat treatment at 100 ° C. for 1 hour, 120 ° C. for 3 hours, 150 ° C. for 1 hour, and 180 ° C. for 7 hours.
[0212]
In this way, the surface layer portion of the resin filler 10 and the surface of the lower conductor circuit 4 formed in the through hole 9 and the conductor circuit non-forming portion are flattened, and the resin filler 10 and the side surface 4a of the lower conductor circuit 4 are formed. An insulating substrate was obtained in which the inner wall surface 9a of the through hole 9 and the resin filler 10 were firmly adhered through the roughened surface (see FIG. 6D). . By this step, the surface of the resin filler 10 and the surface of the lower conductor circuit 4 are flush.
[0213]
(5) After washing the substrate with water and acid degreasing, soft etching is performed, and then an etching solution is sprayed on both sides of the substrate to spray the surface of the lower conductor circuit 4, the land surface of the through hole 9, and the inner wall. Thus, roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 7A). As an etching solution, an etching solution (MEC Etch Bond, manufactured by MEC Co., Ltd.) comprising 10 parts by weight of imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride was used.
[0214]
(6) The roughened surface forming resin composition of B (viscosity: 1.5 Pa · s) is applied to both sides of the substrate with a roll coater, left in a horizontal state for 20 minutes, and then at 60 ° C. for 30 minutes. The roughened surface forming resin layer 2a was formed.
Further, the roughened surface forming resin composition (A) (viscosity: 7 Pa · s) was applied onto the roughened surface forming resin layer 2a using a roll coater, and left in a horizontal state for 20 minutes. Then, drying was performed at 60 ° C. for 30 minutes to form a roughened surface forming resin layer 2b, and a roughened surface forming resin layer having a thickness of 35 μm was formed (see FIG. 7B).
[0215]
(7) A photomask film on which a black circle having a diameter of 85 μm is printed is adhered to both surfaces of the substrate 1 on which the roughened surface-forming resin layer is formed in (6) above, and 500 mJ / cm by an ultrahigh pressure mercury lamp.² After exposure at intensity, it was spray developed with DMDG solution. Thereafter, this substrate was further 3,000 mJ / cm with an ultra-high pressure mercury lamp.² Thickness having a via hole opening 6 having a diameter of 85 μm and excellent in dimensional accuracy equivalent to that of a photomask film. An interlayer resin insulation layer 2 having a thickness of 35 μm was formed (see FIG. 7C).
[0216]
(8) The substrate on which the via hole opening 6 is formed is immersed in a 70 ° C. solution containing 800 g / l chromic acid for 19 minutes to dissolve and remove the epoxy resin particles present on the surface of the interlayer resin insulating layer 2. Thus, the surface of the interlayer resin insulation layer 2 was made rough (depth: 3 μm) (see FIG. 7D).
[0217]
(9) Next, the substrate after the above treatment was immersed in a neutralization solution (manufactured by Shipley Co., Ltd.) and washed with water.
Further, by applying a palladium catalyst (manufactured by Atotech) to the surface of the roughened substrate, catalyst nuclei were attached to the surface of the interlayer resin insulation layer 2 and the inner wall surface of the via hole opening 6 (FIG. Not shown).
[0218]
(10) Next, pretreatment was performed by immersing the substrate in a pretreatment solution for electroless plating having the following composition.
[Pretreatment solution for electroless plating]
NaOH 0.10 mol / l
HCHO 0.10 mol / l
[Pretreatment conditions]
Immersion temperature 30 ° C
Liquid temperature 3 minutes
[0219]
(11) Next, the pretreated substrate is immersed in an electroless copper plating aqueous solution having the following composition, and an electroless copper plating film 12 having a thickness of 0.6 to 3.0 μm is formed on the entire rough surface. Thus, a substrate was obtained in which the electroless copper plating film 12 was formed on the surface of the interlayer resin insulating layer including the inner wall of the via hole opening (see FIG. 8A).
[Electroless plating aqueous solution]
NiSO_Four                   0.003 mol / l
Tartaric acid 0.200 mol / l
Copper sulfate 0.030 mol / l
HCHO 0.050 mol / l
NaOH 0.100 mol / l
α, α'-bipyridyl 100 mg / l
Polyethylene glycol (PEG) 0.10 g / l
[Electroless plating conditions]
40 minutes at 34 ° C liquid temperature
[0220]
(12) A commercially available photosensitive dry film is affixed to the electroless copper plating layer 12 and a mask is placed thereon, and 100 mJ / cm.² Then, a plating resist 3 having a thickness of 25 μm was provided by developing with a 0.8% aqueous sodium carbonate solution (see FIG. 8B).
[0221]
(13) Next, the substrate is washed with 50 ° C. water, degreased, washed with 25 ° C. water, further washed with sulfuric acid, and then subjected to electrolytic plating under the following conditions to form a plating resist 3 non-formed portion. Then, an electrolytic copper plating film 13 having a thickness of 20 μm was formed (see FIG. 8C).
[Electrolytic plating solution]
Sulfuric acid 2.24 mol / l
Copper sulfate 0.26 mol / l
Additive 19.5 ml / l
(Manufactured by Atotech Japan, Kaparaside GL)
[Electrolytic plating conditions]
Current density 1 A / dm²
65 minutes
Temperature 22 ± 2 ° C
[0222]
(14) Further, after removing the plating resist 3 with 5% KOH, the electroless plating film under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide. A conductor circuit 5 (including a via hole 7) was formed (see FIG. 8D).
[0223]
(15) Next, the same process as in (5) was performed to form a roughened surface on the conductor circuit surface (see FIG. 9A).
(16) By repeating the steps (6) to (15) above, a further upper conductor circuit was formed to obtain a multilayer wiring board (see FIGS. 9B to 10B).
[0224]
(17) Next, a multilayer printed wiring board having the solder bumps 17 was manufactured in the same manner as in (17) to (20) of Example 1 (see FIG. 10C).
[0225]
(Comparative Example 1)
A multilayer printed wiring board was produced in the same manner as in Example 1 except that a pretreatment liquid for electroless plating having the following composition was used as the pretreatment liquid for electroless plating.
[Pretreatment solution for electroless plating]
NaOH 0.005 mol / l
HCHO 0.10 mol / l
[0226]
(Comparative Example 2)
A multilayer printed wiring board was produced in the same manner as in Example 1 except that a pretreatment liquid for electroless plating having the following composition was used as the pretreatment liquid for electroless plating.
[Pretreatment solution for electroless plating]
NaOH 0.30 mol / l
HCHO 0.10 mol / l
[0227]
(Comparative Example 3)
A multilayer printed wiring board was produced in the same manner as in Example 1 except that a pretreatment liquid for electroless plating having the following composition was used as the pretreatment liquid for electroless plating.
[Pretreatment solution for electroless plating]
NaOH 0.10 mol / l
HCHO 0.05 mol / l
[0228]
In the multilayer printed wiring boards obtained in Examples 1 to 5 and Comparative Examples 1 to 3, the shape of the electroless plating film and the peel strength of the electroless plating film were evaluated. The results are shown in Table 1. In addition, the shape of the electroless plating film was evaluated by the following evaluation method.
Moreover, about the said multilayer printed wiring board, the continuity test was done and the presence or absence of a disconnection was evaluated. The results are shown in Table 1.
[0229]
(1) Shape of electroless plating film
The multilayer printed wiring board was cut longitudinally so as to include a via hole, the shape of the electroless plating film was observed with a microscope, and evaluated according to the following evaluation criteria.
Evaluation criteria
○. There is no undeposited portion of the electroless plating film, and the thickness is uniform.
×. There is an undeposited portion of the electroless plating film, or the thickness varies.
[0230]
[Table 1]

[0231]
As shown in Table 1, in the multilayer printed wiring board (Examples 1 to 5) manufactured using the pretreatment liquid for electroless plating according to the present invention, the entire surface of the interlayer resin insulating layer has a uniform thickness. An electroless plating film was formed, and the peel strength of this electroless plating film was sufficiently high at 0.8 kg / cm or more, and the obtained multilayer printed wiring board had good connectivity.
On the other hand, in the multilayer printed wiring boards of Comparative Examples 1 to 3, the electroless plating film having a uniform thickness is not formed on the entire surface of the interlayer resin insulation layer, Uneven portions were seen. In addition, the peel strength of this electroless plating film is 0.7 kg / cm or less and the adhesion of the electroless plating film is not sufficient, and the obtained multilayer printed wiring board has some poor connection, The connectivity was low compared to the example.
[0232]
【The invention's effect】
As described above, since the pretreatment liquid for electroless plating of the present invention has the above-described configuration, after pretreatment using the pretreatment liquid for electroless plating, electroless plating treatment is performed. In this case, an electroless plating film that is uniform and excellent in adhesion can be formed on the surface of the object to be plated.
Moreover, since the processing solution for electroless plating according to the present invention has the above-described configuration, the processing solution used when forming a uniform electroless plating film having excellent adhesion on the surface of an object to be plated made of resin. Suitable as
[0233]
Moreover, since the manufacturing method of the multilayer printed wiring board of 1st-4th this invention consists of the above-mentioned structure, it is excellent in the adhesiveness of a board | substrate or an interlayer resin insulation layer, and a conductor circuit, and is excellent in reliability and an electrical property. A multilayer printed wiring board can be manufactured.
[Brief description of the drawings]
FIGS. 1A to 1D are cross-sectional views showing a part of steps of a method for producing a multilayer printed wiring board according to the present invention.
FIGS. 2A to 2D are cross-sectional views illustrating a part of the process of the method for producing a multilayer printed wiring board according to the present invention.
FIGS. 3A to 3D are cross-sectional views showing a part of the steps of the method for producing a multilayer printed wiring board according to the present invention. FIGS.
4 (a) to 4 (c) are cross-sectional views showing a part of the steps of the method for producing a multilayer printed wiring board according to the present invention.
FIGS. 5A to 5C are cross-sectional views illustrating a part of the steps of the method for producing a multilayer printed wiring board according to the present invention. FIGS.
FIGS. 6A to 6D are cross-sectional views illustrating a part of the steps of the method for producing a multilayer printed wiring board according to the present invention.
7A to 7D are cross-sectional views showing a part of the steps of the method for producing a multilayer printed wiring board according to the present invention.
FIGS. 8A to 8D are cross-sectional views showing a part of the process of the method for producing a multilayer printed wiring board according to the present invention. FIGS.
FIGS. 9A to 9C are cross-sectional views illustrating a part of the steps of the method for producing a multilayer printed wiring board according to the present invention. FIGS.
FIGS. 10A to 10C are cross-sectional views illustrating a part of the steps of the method for producing a multilayer printed wiring board according to the present invention. FIGS.
[Explanation of symbols]
1 Insulating substrate
2 Interlayer resin insulation layer
3 Plating resist
4 Lower conductor circuit
4a Roughened surface
5 Conductor circuit
6 Via-hole opening
7 Bahia Hall
8 Copper foil
9 Through hole
9a Roughened surface
10 Resin filler
12 Electroless copper plating film
13 Electrolytic copper plating film
14 Solder resist layer
15 Nickel plating film
16 Gold plating film
17 Solder bump
18 Through hole
19 Solder

Claims (7)

A method for producing a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate, and these conductor circuits are connected via via holes,
The manufacturing method of the multilayer printed wiring board characterized by including the process of following (A)-(F) at least.
(A) a step of applying a catalyst to the surface of the substrate or the interlayer resin insulation layer;
(B) From an aqueous solution containing 0.01 to 0.25 mol / l of an alkaline compound and 0.1 to 0.3 mol / l of a reducing agent on the substrate or the interlayer resin insulation layer provided with the catalyst. A step of performing a pretreatment using a pretreatment liquid for electroless plating ,
(C) At least one selected from the group consisting of alkaline compounds, reducing agents, copper ions, tartaric acid or salts thereof, nickel ions, cobalt ions, and iron ions on the pretreated substrate or interlayer resin insulation layer Forming an electroless plating film using an electroless plating solution comprising an aqueous solution containing metal ions of
(D) forming a plating resist on a part of the electroless plating film;
(E) forming an electrolytic plating film on the plating resist non-forming portion; and
(F) The process of removing the electroless plating film under the said plating resist, after peeling the said plating resist. The method for producing a multilayer printed wiring board according to claim 1 , wherein the temperature of the pretreatment liquid for electroless plating in the step (B) is 20 to 50 ° C. The method for producing a multilayer printed wiring board according to claim 1 or 2 , wherein the pretreatment time in the step (B) is 0.5 to 5 minutes. A method for producing a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate, and these conductor circuits are connected via via holes,
The manufacturing method of the multilayer printed wiring board characterized by including the process of following (a)-(f) at least.
(A) providing a catalyst on the surface of the substrate or the interlayer resin insulation layer;
(B) From an aqueous solution containing 0.01 to 0.25 mol / l of an alkaline compound and 0.1 to 0.3 mol / l of a reducing agent on the substrate or the interlayer resin insulation layer provided with the catalyst. A step of performing a pretreatment using a pretreatment liquid for electroless plating ,
(C) At least one selected from the group consisting of alkaline compounds, reducing agents, copper ions, tartaric acid or salts thereof, nickel ions, cobalt ions, and iron ions on the pretreated substrate or interlayer resin insulation layer Forming an electroless plating film using an electroless plating solution comprising an aqueous solution containing metal ions of
(D) forming an electrolytic plating film on the electroless plating film;
(E) forming an etching resist on a portion of the electrolytic plating film; and
(F) A step of removing the electrolytic plating film and the electroless plating film under the etching resist non-forming portion by an etching process. The method for producing a multilayer printed wiring board according to claim 4 , wherein the temperature of the pretreatment liquid for electroless plating in the step (b) is 20 to 50 ° C. The method for producing a multilayer printed wiring board according to claim 4 or 5 , wherein the pretreatment time in the step (b) is 0.5 to 5 minutes. The concentration of the alkaline compound is 0.025 to 0.25 mol / l,
The concentration of the reducing agent is 0.03 to 0.15 mol / l,
The concentration of the copper ions is 0.02 to 0.06 mol / l,
The concentration of the tartaric acid or salt thereof is 0.05 to 0.3 mol / l.
The manufacturing method of the multilayer printed wiring board in any one of Claims 1-6 using an electroless-plating liquid.

Images